Nathan, thanks for the reply.
Originally Posted by ntenny
I believe -- could be mistaken -- that the #3 f/14 Perigraphe is in the same barrel as the #1 and #2. I have #1 (60 mm) and #3 (90), their barrels are slightly loose fits in an Ilex #3, slightly looser fits in an Alphax #3. A bit of darkroom tape on the shutter's threads makes the fits more secure.
My #1 is stuffed into the front of a truncated Ilex #3, you can read about it and see pictures at http://www.galerie-photo.com/telecha...2011-03-29.pdf , where there is also a discussion of changes over time in Berthiot's coverage claims. That shutter's rear tube was shortened to reduce vignetting. Your 120 shouldn't have vignetting problems if stuffed into the front of an unmutilated Ilex #3.
About coverage claims. The latest for f/14 Perigraphes is 100 degrees, in which case (a) no movements on 8x10 and (b) softness in the outer 7 mm or so of the corners.