The best resource for finding out about the R-D1 is the dedicated r-d1 forum on rff (
www.rangefinderforum.com).
Rich Cutler has an exellent page on it here:
http://www.richcutler.co.uk/r-d1/r-d1_01.htm
Since you are in Europe, you might want to consider buying it from Robert White:
www.robertwhite.co.uk. They seem to have the best after-sales support for the R-D1 anywhere.
If you are going to go with the R-D1, please be aware that rangefinder alignment is often an issue. If its needs adjustment, Don Goldberg (DAG) is the man.
I also learned from Don what may be the most important tip when using the R-D1:
When focussing for a shot, accurate focus is best achieved by pulling the focus in from FAR to NEAR, not the other way around.