I managed to acquire this pen from fellow fpn'er univer. When I finally got a chance to look at it, it ends up a variant I haven't acquired.

From the onset, it looks like your standard early dip-less with red taper:


The trim ring adds a nice touch, don't you think?

The nib is an original 5668 with original feed:



You pull the lever up with a coin or fingernail, and the nib and feed release from the holder. Then you can just replace the nib, instead of the whole nib/feed unit. This was a much more economical way for "public" pens in banks, post offices, and the like, to replace bent nibs.

This one is stuck closed, and by the looks of it, I could see these corroding and breaking easily, which is probably why later dip-less were advertised as accepting both this style nib as well as the re-new-point. If true, this partly explains why so few of these pens are seen today.

Incidentally, this one has the Esterbrook Pat Pend Made in USA DIP-LESS imprint, unlike those with the DIP-LESS UNIVERSAL imprint. I wonder if the DIP-LESS UNIVERSAL pens were the answer to this pens problematic feed lever? Antonios? Gerry? Anyone?

Best-
Brian

Nice pen! It must be rare for you to come across an Esterbrook variant you don't already have in your collection, Brian

Speaking of Dip-Less desk pens......
I sent you a little email about a question about my brand new 444 Dip-Less desk set, but I'm not sure if your email addy is the same as it once was. If you didn't get the email, I can resend it to you (or perhaps I should have just started an FPN thread with my questions )

Nice pen... I declare total ignorance in desk pens