I recently acquired a nice, unrestored Waterman 3 from the early to mid 1930s, in great condition save for a broken feed. Upon removing the remaining length of the feed from the section to commence with the pen's restoration, I noticed that the feed has 2 parts- the feed and an outer sleeve. I have never seen a 2-piece sleeved feed on a Waterman, although I have only restored a few other Watermans (a Purple 5, a 52, and a Dauntless). All things considered, this is the only US-made vintage pen I have found to have a 2-piece sleeved feed (in my limited experience, of course).
I've been trying to locate information on this 2-part feed design, and I've come up with nothing. I'm planning to replace it with a spare Waterman #2 sized feed to match the nib and section so I have a usable pen. I feel like I may have stumbled upon an experimental/short-lived design, although it's worthless to collectors (and to me) since it's broken. However, I was wondering if there are any Waterman fans or collectors out there with more experience that might know more about my mystery 2-piece feed?