Hi,
You say "And his output over the years was amazing." and really I don't know how to answer that except to say that 6 cassettes of 35mm film a day is 225 frames roughly and he was going for a good many years. And as his hobby was photography I expect he did it 7 days of the week, making 1,575 pictures a week... That's assuming the 6 films a day is correct, of course.
And, as I said, at first few were using Leica but were taking one picture at a time then changing the plate and so on and spending hours developing them individually. Any 35mm user can develop 36 to 40 pictures in the time it took others to develop one plate. Time in the chemicals is the same, like the trick question about boiling three eggs.
I hope that doesn't sound rude, it's not intended to be; I'm just in favour of looking at the reality of it. I'd love to be able to afford the time and money to do it but then I can't. Now if someone would care to donate a new M9 and a Tri Elmar I'd have a good go at doing the same.
Regards, David