Quote Originally Posted by mikebarger View Post
Besides the year code they have a hole in the front plate, top left as you look at the front of the camera, that allows for access to a screw for service. Reason may not be right, but there is a hole there.
The reason is indeed not correct. The holes were part of the mount for a planned add-on winder that never materialized (they made the EL series instead).

P.S.
See that John already gave that info. My apologies for the redundancy.

Quote Originally Posted by mikebarger View Post
You don't see many old C's around.
That's the way it goes with old things. They are lost, put in boxes, stuffed away in cupborads, attics, etc.
Does not mean that they have all died, nor that they will not be any good anymore. I have a bunch of old C lenses that still work perfectly good.