Waterman Red Ripple Barrel End Cap?

[smackyf]

I recently purchased a red ripple Waterman fountain pen. The barrel diameter is the same as a no. 55 and has a no. 5 nib. It does not have a cap and the barrel is not threaded for one. It has a barrel end cap that unscrews revealing a black threaded stud. Photos attached.

 

I found a photo of a combination desk pen with the same stud, so I’m guessing that this is what this pen was. I’m curious about the end cap though. Did desk pens originally come with an end cap? It’s the same hard rubber as the pen and doesn’t look like it was made later.

 

Thanks for your help.

[Left FPN]

I suspect it is a desk pen giving the user the option to have the long tail or standard length barrel.

 

It might also have been better from a packaging/transport point of view.

[Mr_Pommeroy]

This is interesting. I have not seen any such option in Waterman catalogues from the period (though I am not an expert).

Another explanation could be that the former owner had his desk pen customized. Maybe someone simply cut off the major part of the rearmost piece of the barrel, leaving only the stud. Just a thought.

[smackyf]

Thank you for your replies and thoughts on this. I never seen it before either and thought it was interesting enough to share.