I recently inhereted a 500 C w/ the mentioned lenses and backs. I remember my grandfather always carried this camera on the many hikes we had together in the mountains of Tennessee. It was his "point and shoot." How can I get owner's manuals for the body, lenses, backs, etc? He bought the outfit new in the mid sixties, I believe. The shutter crank on the right side of the body has a contained light meter that appears to be original. Was this part of a latter model. None of the pictures I have seen of the 500 C has this configuration.