I have a sharkskin IIIc from 1949. My Grandfather gave it to me back in the 1970s. (
Some pictures of my grandfather with the Leica.) The shutter acted up in the late 1970s and it sat on a shelf for 27 years. I took it off the shelf a couple of years ago to find that the shutter curtains now also had pinholes. But shooting that test roll was a revelation. I had forgotten. A year ago it had a CLA and new shutter curtains and is as a sweet a shooter as I could want. The Summitar still needs a CLA and haze removal. That's next.
I've been wanting a Leica Standard. They are so elemental, but way beyond my budget, so I bought a former Soviet Union Zorki 1 with a bad rangefinder and am turning it into a Zorki Standard. It has a 35/2.8 Jupiter 12 and an Industar 50/3.5 Elmar clone. There is
a thread over at the Rangefinder Forum covering that project.