Pen Model ID Request - Onoto The Pen, Thomas de la Rue, Plunger Filler - likely early 1920's, ebonite, clipless

[IHaveAPenProblem]

Hello all!

 

I've heard a lot about this place, and have finally been pushed to actually sign up.  And the challenge I have is in trying to identify the model of a beautiful, but very well-used Onoto plunger fill, which I picked up cheaply off a market in its home town, when I was visiting a friend in the Big Smoke!

 

The model number is poorly imprinted, and given the wear, it seems to change depending on what I have for breakfast.

 

Online research, suggests this is a 5000 series/streamline version from the early 1920's - so a real antique. However, when I was looking to buy the parts to fix it up, the numbers don't match. The model ID from Custom Pen Parts (https://www.custompenparts.co.uk/gb/content/7-onoto-model-identification).  On my pen, the diameter matches the medium slim, however, the barrel length matches the short. So I appear to have a 'medium slim short', which doesn't appear on the list!

 

As it was, I managed to pick up another Onoto 5601, with a wrecked nib, which helped me with proper disassembly, and the internals were the same, so both pens take a 7.65 mm seal, though this one has a shorter rod.

 

The imprint. From what I can see, the first digit has something that could be the end of the top part of a '2', and I suspect the second digit is a 3. The final two digits are either 0/6/8 - but that's dependent on the font. Honestly, I could be seeing scratches and dings, this pen has had a hard life, and I suspect the imprint was never good.

 

Whatever the pen model is, it's far from my typical pens I like, but I've fallen for this hard. The nib is a beautiful smallish italic, with reasonable flex. I can't fault it, and I'm certainly sold on vintage Onoto's now!

 

The ink is Diamine Ancient Copper, and don't worry about the nibless 5601 - I had a spare TDLR nib from a later pen, I was fixing up for a friend, which I found had a cracked nib. It was a special pen she was given by her dad, back in the 50's for her "plus 9's" exams, and she has so few things to remember her father with, she didn't want the nib swapped, so I sadly had to hand it back to her still not working, but did mount it in a frame for her to still enjoy. Yeah, so the 5601 is just waiting to be inked up.

 

 

[boilermaker1975]

@IHaveAPenProblem You could email Onoto the photos, Onoto <info@onoto.com>, and I am sure they could tell you. The one time I emailed with a question they were very responsive.

[IHaveAPenProblem]

29 minutes ago, boilermaker1975 said:

@IHaveAPenProblem You could email Onoto the photos, Onoto <info@onoto.com>, and I am sure they could tell you. The one time I emailed with a question they were very responsive.

 

I think that's going to be my best option at this rate. I had thought someone with a particular penchant for Onoto pens might pick this up, or maybe someone with the Onoto book, bit alas, no fish have bitten yet!

[boilermaker1975]

35 minutes ago, IHaveAPenProblem said:

 

I think that's going to be my best option at this rate. I had thought someone with a particular penchant for Onoto pens might pick this up, or maybe someone with the Onoto book, bit alas, no fish have bitten yet!

 

I only became aware of Onotos a few months back when @ParramattaPaul posted a photo of the BRG Onoto Scholar. It was such a great looking pen I ordered it. Since then I have also bought the Faraday and I am salivating over several others! 

 

So I am pretty naive about Onotos, especially vintage ones.

[ParramattaPaul]

1 hour ago, IHaveAPenProblem said:

 

I think that's going to be my best option at this rate. I had thought someone with a particular penchant for Onoto pens might pick this up, or maybe someone with the Onoto book, bit alas, no fish have bitten yet!

Another vintage pen authority who may be able to provide an answer can be contacted at:  De La Rue Onoto Pens

[IHaveAPenProblem]

10 hours ago, boilermaker1975 said:

 

I only became aware of Onotos a few months back when @ParramattaPaul posted a photo of the BRG Onoto Scholar. It was such a great looking pen I ordered it. Since then I have also bought the Faraday and I am salivating over several others! 

 

So I am pretty naive about Onotos, especially vintage ones.

 

So I do know their last pen was either the K1 or K2, before closing down the pen part of the business, back in the 1960's. They carried on and were printing banknotes and passports until the the 2010's. I believe their main site was taken on by the Bombay Sapphire gin distillery in Hampshire UK. A lot of information was lost when the head office in London was bombed out in the war.

 

The current company does build on the heritage, but is independent of the original, which is why I haven't assumed to ask them directly. I assume they'll pivot pull the

[ParramattaPaul]

They might surprise you. I suspect they thoroughly researched everything.  It's unlikely that they would attempt to trade on Onoto's history and reputation without knowing the nuts and bolts with which they were built.

[IHaveAPenProblem]

I phoned them with a request before, and they told me to email it. I emailed, but never got a reply. It wasn't a big deal, but I've emailed David from Vintage Pens, and will await to see if I get a response from him first, and then move onto Onoto. 

[IHaveAPenProblem]

So, I'm non the wiser on the model number.

 

I've emailed everyone suggested, and posted in several forums, but still, not a bite! 

 

Does anyone have the Onoto book they'd be willing to try looking it up in, maybe? Anyone? 

[ParramattaPaul]

29 minutes ago, IHaveAPenProblem said:

So, I'm non the wiser on the model number.

 

I've emailed everyone suggested, and posted in several forums, but still, not a bite! 

 

Does anyone have the Onoto book they'd be willing to try looking it up in, maybe? Anyone? 

I don't, not yet. Check back in a fortnight. 

[ParramattaPaul]

On 6/27/2025 at 9:06 AM, IHaveAPenProblem said:

I've heard a lot about this place, and have finally been pushed to actually sign up.  And the challenge I have is in trying to identify the model of a beautiful, but very well-used Onoto plunger fill, which I picked up cheaply off a market in its home town, when I was visiting a friend in the Big Smoke!

 

The model number is poorly imprinted, and given the wear, it seems to change depending on what I have for breakfast.

 

Online research, suggests this is a 5000 series/streamline version from the early 1920's - so a real antique. However, when I was looking to buy the parts to fix it up, the numbers don't match. The model ID from Custom Pen Parts (https://www.custompenparts.co.uk/gb/content/7-onoto-model-identification).  On my pen, the diameter matches the medium slim, however, the barrel length matches the short. So I appear to have a 'medium slim short', which doesn't appear on the list!

 

As it was, I managed to pick up another Onoto 5601, with a wrecked nib, which helped me with proper disassembly, and the internals were the same, so both pens take a 7.65 mm seal, though this one has a shorter rod.

 

The imprint. From what I can see, the first digit has something that could be the end of the top part of a '2', and I suspect the second digit is a 3. The final two digits are either 0/6/8 - but that's dependent on the font. Honestly, I could be seeing scratches and dings, this pen has had a hard life, and I suspect the imprint was never good.

 

Whatever the pen model is, it's far from my typical pens I like, but I've fallen for this hard. The nib is a beautiful smallish italic, with reasonable flex. I can't fault it, and I'm certainly sold on vintage Onoto's now!

 

The ink is Diamine Ancient Copper, and don't worry about the nibless 5601 - I had a spare TDLR nib from a later pen, I was fixing up for a friend, which I found had a cracked nib. It was a special pen she was given by her dad, back in the 50's for her "plus 9's" exams, and she has so few things to remember her father with, she didn't want the nib swapped, so I sadly had to hand it back to her still not working, but did mount it in a frame for her to still enjoy. Yeah, so the 5601 is just waiting to be inked up.

 

The Onoto book arrived yesterday via DHL.  It's chocker block full of information and top-quality photos.  I'll have a Captain Cook at it tonight to see if I can find your pen or relevant info.

[ParramattaPaul]

I had a Captain Cook (rhyming slang for 'look'.  Yeah, I'm that old!) and from what I discern the above-mentioned pen appears to be a model 3500 made circa 1925.  Certainly a 100 year old pen qualifies for Vintage status.

[IHaveAPenProblem]

Thanks @ParramattaPaul, I've only just got the alert for your response - 7 hours later

 

Thanks for your time and effort, but there may still be some discussion. I'd ruled that model out based on Custom Pen Parts listing that as too long. But they may have made short versions of it?

 

Mine is very much thin and short, which is the main challenge with it. 

 

The sizes from Custom Pen Parts are listed here: https://www.custompenparts.co.uk/gb/content/7-onoto-model-identification

[IHaveAPenProblem]

Before I stripped it, I took some photos, which I've added to this post. Of course, the pin went straight through the number, which won't help now.

 

I honestly don't know why it looks so much better now, I've not polished the pen at all! 

 

I'm tryna of the digits, it would be useful to have a reference of the typeface used but...

1st - anyone's guess, and I'm not sure there is one!

2nd - 5 (possible 3?)

3rd - 6 (possible 0)

4th - 0 (possible 6 or 9, but this one seems offset).

 

So best guess is  560? What do you think?

 

Edited July 15 by IHaveAPenProblem
Removal of excess photo

[ParramattaPaul]

The barrel legend (imprint, style. and font) is correct for both the 5000 and the 3500. The nib is correct for the 3500.  To me, the three visible digits on the end cap appear to be a 5, an 0 or remotely possibly an 8, and an 0.  There is what appears to be the top of a 3 or even a 2 preceding first (5) digit.   This leads me to a third possibility.  That is model 2500.

 

Let get my day started.  I'll send an update when I've had a chance to look further.