For detailed information I refer to [I] ... Another good resource is Leica Manual by Willard D. Morgan and Henry M. Lester, published over many years in several editions.
I also have found that the Morgan and Lester book has some very useful information about fundamentals and techniques of 35mm rangefinder photography. It would probably be of considerable interest to those who shoot with FSU Leica inspired cameras too.
Henry A Certified Dinosaur
Nikons F, F2, D700, Leica M3, & Kiev 4a