What about mounting rangefinder-coupled Leica screw-mount lenses from the twenties on a 2021 Leica digital body?Yes. My original model EF 300 2.8 still takes amazing images. I think it's remarkable that Canon built a system in the late 80's such that you can still mount those lenses on an R5 from 2020 and do amazing work. I can't think of any other piece of expensive high technology that is so backwards/forwards compatible. Not that I still don't miss my FD 400 2.8.
And Leicaflex 1964 lenses on a 2021 Leica SL2 body?