Mitch, you might find that the Skopar won't cover (even at f/22 or f/32) where the triplet Agnar does (I've read that the Tessar type lenses have less coverage than some triplet designs -- but I'm not sure if the Agnar is a Cooke triplet or the type with PCX front and rear glass and reverse middle element compare to the Cooke, and I'm certain a Cooke has less coverage than a Tessar type) -- but since you already have it, it's certainly cheap to find out. My Agnar just covers 4x5 at those openings, slight corner loss when focused to infinity, almost undetectable corner loss when set hyperfocal. I've got a couple 5x7 film holders, one of which has broken wood -- I think I'll cut one of those dark slides to fit the 4x5 and leave a 56 mm slot, mark the ground glass, and have some fun with my Speed.

I'd certainly test the lens on sheet film before getting a roll back -- and for my methods, I don't know that I'd care about a roll back at all, as long as I can get some more film holders. Might have to post a trade deal...