You can't give more than a generalised answer to this age old question. I've had more or less all the cameras mentioned and - I hope - handle them all the same. From time to time they need a general check up and so on and then off we go again and another starts to feel off and goes away for a check.
At the moment the Leica II feels fine to handle but I know the shutter is not running smoothly. The FED I last handled will go next but the Zorki feels fine as does an older ('36) FED. I hope this shows the problem.
I've also a Leica standard I think was abandoned when the war ended and a better one was liberated. The standard had lubrication problems, a rusty screw inside and badly needed a complete service but talking to the technician I was told it hadn't been used very much as it was "as new" apart from the oils, greases and the screw.
And I've a IIIc waiting for film to go through it after a repair and a '39 FED being repaired.
In a nutshell, you are buying second-hand and a II or III will be about 80 years old. So you have to accept that it is just pot luck what you get. You'll know after the first film or two...
Afterthoughts (edited, in other words); I've just looked at your list of cameras and I think it is too late as the bug has bitten you and you will end up with one of eveything and two of some of them. So what does it matter where you start? OTOH, the Leica II is a classic, simple and straight forward and very little to go wrong compared with others.
PS To my odd way of thinking it makes more sense to put a Leica lens on a good old USSR body but that's just for taking pictures. There's a lot more comes into it but mostly it seems to me to be curiosity driving us.
Last edited by David Hughes : 06-04-2019 at 12:23.
Reason: Those CRLF again...