I've updated my Leica M article series with a new page 43 on how to focus the Rangefinder / Meßsucher
The Decisive Moment - Focusing the Leica M - Part 2/5
This is the 2nd of 5 new pages on focusing a Leica M. The first page is also online here:
The Minority Report - Focusing the Leica M - Part 1/5
Feel free to comment and suggest further tips. Next page is on using the EVF