Fred,
We looked into N12M back in 1999. A fellow over on the eastern slopes of Montana owned it at the time... however back then he was asking considerably more for it than the current asking price, which I understand to be around $125K. It has all original 400 gear and a few add-ons and from what the owner sent me, it appeared to be a good bird.
Here's a website with specific info on the ship:
http://home.earthlink.net/%7ewhiting.../Cessna337.htm
Certainly the airframe and engines are low time, the paint is very shiny, the leather looks good and the panel is very clean, with the addition of a King KLN-88 and Hoskins CFS-2000A, and of course since it has the 400 servo encoding altimeter, it also has the backup over on the right panel, plus the very nice DUAL head 400 ADF.
MyAirplane.com doesn't show any derogatory data, and I recall the only thing that had been replaced while the Montana owner had it was some rudder skins from hangar rash.
Had the price been right back in 1999, we would have opted, but along came a 1977 with 1100 hours TT, and well, we were smitten!
Hey, if the prospective doesn't take it, let me know because I have a close friend with a low wing who also has the bug for a nice P337... and since it will be in Oklahoma... it's almost half-way home to the left coast. I'm sure my buddy would come see it while it's there, so let us know.
SkyKing