The 500CM was introduced in 1957 and remained in production until 1970, my one is from the mid "60s and is very worn. I shot exclusively on Ilford Hp5 developed in Kodak D76 or ID11 (pretty much the same developers). For a camera this old it didn't miss a beat, no light meter so I guestimated the exposures and mostly was pretty close. The Reciprocal Rule works like this-
The ISO equals the shutter speed at f16 on a bright sunny day. So for the 500cm with 400 ISO film it works out as: f16 at 1/500 sec.
Scanned on the Nikon LS9000 scanner using SilverFast, slow but the quality is amazing.
I worked around that, opening up in the shadows by a couple of stops as needed, usually works fine and is a hell of a lot quicker than stuffing around with light meters.
Still have to do an edit