This pen belonged to my Grandfather who died before I was born. My Grandmother says he had it in the 40s, but it could have been any time up to the early 70s.

I have attached some large pictures of the pen and its markings. Any information about this model of pen would be most welcome!

I think I see hallmarks indicating it is sterling silver and the cap says it gold plated. Of course the nib is 18K solid gold. I am not familiar with the model but it sure looks like a great pen.

Perhaps it is a JIF Waterman from France...

1940s? I don't think it looks that old...

More like the 1950s or later...

Thought she was a bit off that's why I said could be any time up to 70s



Is that what ORG means?

In my opinion the pen is a gold plated (plaque or) Waterman "CONCORD", a model of the early '70s. I do not know the meaning of the G after PLAQUE OR.
Regards, Giuseppe

Thank you! You're right, after a bit of searching I found this:
Similar pen on FPN
same pen on eBay

I sold the pen referred to and have confirmed The Concord name to DJ HUNTER back channel and my source was of course the wonderful 'Fountain Pens Of The World' by Andreas Lambrou.
If you can't find it anywhere else it is most likely in there!
Beg or borrow a copy and settle down to four or five weeks of entertaining evenings, you'll nae hae ony greetin!!!
except perhaps in envy.

Thank you very much for your help, it's very satisfying to find out a bit about this pen, something I'm not used to as all my other pens are not exactly rare!