Mark your lens is missing the Waterhouse stops(Do a search as there is a bunch of threads on the subject). In short the early lenses had a slot cut in the barrel & the lens came with a set of stops that slide in this slot. Very accurate but often missing. I got kind of lucky with this one as it has a full set. You will find that they are not difficult to make yourself. Again, do a search on Waterhouse stops Making them, calculating stops & just about any info you will need. It has already posted in a thread.

I would willing to scan them & email them to you sometime next week. This way you could use them for a template & have the original sizes in the Voigtlander set.

Quote Originally Posted by Mark Paschke View Post
Yes and thanks again, I may be a lil hosed here. The "Tab" sticking out of the Voightlander must be the iris? My large lens is missing this and I notice inside the lens theres 2 screws and a bracket on opposite sides, my guess is Im missing the original iris?

Mine is a
5
Euryscop

No.32306

Voightlander & John
Braunschneig

Can I find that "iris" if thats what its missing, Im also missing lens caps but have a lens hood