I cannot comment on the Canonet, but I have made similar experience with some Olympus RD. However, my intentions were never serious. I bought two RDs that were labeled defective just to do some post-mortem examinations :-).
Then I bought two more, completely disassembled them, cleaned all parts in an ultrasonic cleaner, re-lubricated the mechanics and have now two RDs that look and feel like new ones. But for serious photography, I still prefer other cameras, basically because 35mm on the light table always reminds me of stamps and not of real negatives ;-)