I have a super-clean Bausch&Lomb Zeiss-Tessar 1b 5x8 barrel lens, that came off a 5x8 Graflex. It does f/32 and appears to be a 210mm. I want to mount it to a 4x4 lens board for my 5x7 but can't seem to find a mount flange. It will look something like this
My lens is almost identical to that one but is a 5x8. The glass elements are super-clean and the whole thing was serviced before I bought it.
The lens definitely covers 5x7 I've freelensed it in front of the ground glass and the image it makes is nothing short of glorious.