Hi Dan,
your articles about 6x9 lenses and Apo-Nikkors have been religiously saved on my HD, together with your collaboration with E. Bertrando about Boyer lenses.
All of them are very informative, anybody interested in those matters should read them.
There is one small problem though... i guess that the availability of information, and the well deserved consideration for some Boyer lenses, helped a little bit in driving up the prices

Back to the thread:
i guess i have been lucky, all the Alphax No.3 i found have properly dimensioned diaphragms.
Some Polaroid shutters have that problem, both Prontors and Copals. I think that all the 75mm focals are affected, and some 105mm ones. 127mm's are a safe bet.
Unfortunately there is practically no use for a No.1 shutter with restricted diaphragm. The only lens i am aware of is the Kowa Graphic 150mm f/9.
For front-mounting, a better choice ( as explained in the document linked by Dan Fromm) are the Polaroid MP-4 shutters with no diaphragm.

have fun


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