Okay, I've migrated this over here so it doesn't clutter up the other thread.

This Duofold came with another from the UK. It is a button filler and is pre AF (or 1946-48 according to https://parkerpens.net/ukduofold.html)



Note, it is the one at the top of the picture. Note also the flared section end.

The button filler is "gold" coloured, and the section is friction fit. As can be seen here.



The barrel does have an imprint that clearly says it is a Duofold.


So, the problems I have are this:

1. The cap is missing the tassie and clip, but is otherwise damage free.
2. The pressure bar is missing.
3. The ink bag is missing.

Of these three problems I can fix 1 & 3 myself (if I can source parts). Problem #2 is the tricky one. I do not know how to do this.

Is it worth attempting #2 myself - without any special tools or knowledge - or is it better to send it away (I am thinking Danny Fudge maybe able to do this)?