I don't know, Barry. We used to have a whole lot more mounts than we do today, in the AF world.
Minolta SR (MC/MD)
M42 - Used by a ton of Mfgs., early Pentax, Ricoh, Miranda, Fugi to name a few.
I probably missed a few others.
In addition, there were a lot more Medium Format cameras and mounts, too:
So I think that there was a time, when every company didn't have to be billion dollar companies with thousand of employees, that we supported a lot more mounts!
A couple of a350's, an a700 and now an a580, plus even more lenses.