Finally got around to working on the sticky shutter of my 1957 German Kodak Retina IIIc. I think it just has some gunk in it - I took out the lens elements and gave it a thorough, gentle cleaning with some alcohol and it seems to be firing happily at normal speeds (slow speeds, 1/15th and slower, are still kind of sticky, but that’s common in a lot of old cameras, and I don’t plan on using the Retina in very low light, so I’m not bothered).