The change of centimeters to inches is easily done at any of the websites that convert for you.
This works pretty quickly.
The Anastigmatic should be either an 8 in. (the precursor of the 203mm Ektar) or a 170 mm common on 3A folders. Either one should cover the 4x5 format of that Premo 6 with no real issue. Both are pretty nice lenses for their time.
The format of the 2c was just under 3x5, so that lens may work as well. The aperture markings are the old US system. US 16 equals f16 and you can count up and down from there. US 4 to US 128 is f8 to f64, if I'm not mistaken.
Changing cells around between lenses can give you all sorts of different images. The Rapid Rectilinear is convertible so you can remove the front cell and shoot with the rear only or replace the rear with the front and get three different focal lengths. A B&L 5x7 Rapid Rectilinear that I have works as an 8 in. a 12 in. and a 14 in. Using both cells gives me the sharpest image, which is actually quite sharp indeed, considering the age of the lens. Changing cells between shutters works fine as long as the distance between the front cell and the rear cell remains the same. If you change that distance, you may have a lens that will not resolve an image. Mixing cells from two different lenses? Try it and find out. You may have a wonderful Frankenstein of a lens, you may get crap. Just mark them for eventual return to the original to save yourself a lot of grief.
Around Boston is a good place to be for this kind of thing. Come next week to the PHSNE show and sale in Wakefield. I'll be there on Saturday but there are lots of folks there who have
forgotten more than I'll ever know ready and willing to talk cameras.
