I meant to say FM3A. In a nut shell... The FM2n, FM2 & FM have all manual settings with meter built in. The FE & FE2 have auto meter with aperture priority or manual settings but battery dependent. The FM3A has a hybrid shutter, all manual with or with out batteries or with auto metering with aperture priority... You can still have all of them repaired although I have an FE I bought new in 1980 that has been to hell and back... I sent it for a tune up recently and all it needed was a cleaning and new seals for the back and mirror.

I love the Leica M's but out of my cost frame. Not sure this was mentioned but the Bessa rangefinders are a great buy. I had one and love it but it didn't do well with heavy use. If your not shooting many rolls per-day or whatever, it would serve you well...