I have a T-R in a Betax 4. The front element has no focal length on it, just 8 x 10 Gundlach (Fairport) Ser II plus serial number and an illegible f #
Rear cell has Turner-Reich 21" written on it
Shutter aperture scale has 13", 25" and 20"
Since the rear element is marked 21" instead of 20 I suspect it isn't the original cell. Any way to tell the FL of the front element? I don't have a flange/lens board for it yet so can't just mount it on the camera and see.
Is there such a thing as a relatively complete listing of the various elements as well as combined Focal Lengths>