I think I'll just stick with using a handheld meter. Found out the Auto 35B that I was going to use as a donor really does work. Like some other cameras, you have to have film in it for the shutter to trip. I did the sprocket rolling thing before, but thought that something wasn't catching, so the camera was done for.
But after messing with it this morning, I discovered that you have to have the sprocket gear in the right position before the shutter will release. Stuck a roll of test film in it, and whoopeee, it works! And someone else has informed me that the Retina meter is a sealed unit, so I would have to replace it with a like model. Not likely Kodak kept the same build for the Auto 35B as what went in the IIIC.
Got some good shots with the IIIC the other day, despite the ergonomic nightmare it is. Nothing but the shutter release seems to be in the right place.
PF