Ah! What a beauty! Never Never sell it. Just use the hell out of it. I bought my M6 new in 1990 and although it has been well used it has not been abused ( not counting the day I shot for 8 hours straight in pouring rain with another leica user for a charity on a Day Without Art) If your camera has the Leica passport warranty, regardless of whether you think the camera needs a cla, send it in for a complete cla the month before the warranty runs out. No Matter how you think the camera functions now, when you get it back from that cla , years from now, it will be running better than it runs now. I did this with my M6 and I coudn't believe how smooth the camera worked after that first cla. Not to say it wasn't running great before the cla. Its like these cameras are made so damn well that it takes a few years of real use to "break" them in. Incredible machines. I love my Leicas, M6 and M4.