Dan, this is an excellent resource.
I question some of the data in the section on the Rolleiflex 3.5F. As far as I know, this model never had a Tessar lens. I think maybe 'Tessar' should have read 'Planar'?
According to the serial # on my 3.5F, I have a 3.5F III-2, which corresponds to the year I know it was built. But my lens is a Planar, so I think that should be added to the Xenotar.
Gene