One thing I will say is that while we state gear does not matter, it does in one respect. You have been working on mastering a technique that accommodates the limitations of your instrument specifically a Leica IIIC with a Russian clone. This forces you into a major box. Limited shutter speeds, limited focus range, limited ability to focus, no meter, and two viewfinders.
I say this because when a beginner buys something like a Digital Rebel, it has very few limitations and in fact can make every relevant decision for the user except for composition, which I think is the hardest part of photography to master second only to properly choosing exposure (aren't these two related in many ways?). In other words, the lack of limitations with the Rebel is not instructive whereas the limitations of IIIC are instructive. That IIIC has forced you to "read light" as you state, learn equivalent exposures based on stopping down the lens inversely to opening the shutter to maintain proper exposure, and seeing with your mind's eye the composition before it happens i.e. one of the major reason a person uses scale focus because you are anticipating a moment before it happens. You can't be more ready than that....
