Upload & Sell: On
How good are your eyes? Because as good as they are, you're still looking (no pun intended) at autofocus SLR bodies that divert 40% of incoming light to an AF sensor.
Are your conversions of the Leitax type, or are they adapters that can be dismounted?
Me personally, I wouldn't shoot my Summicron R 50 on my EOS-1N, I'd use my R9 because manual focus is that much easier on that body and of course it's coupled for full-diaphragm metering.
Again, I'm being contrarian but sometimes a nudge from an unexpected side gets you thinking about...well, the unexpected.
There's also an EOS film body that was non-AF, I think it was the EOS EF-M and has a screen and viewfinder specifically designed for manual focus. I have pretty gnarly refraction that contact lenses mostly correct, but in 2012 the eyesight in my right eye worsened quite a bit, hence my comment prodding you consider something besides the (deservedly) popular choices above.