I have 3 immaculate heavily "adjusted" bolt-modded Ms, 2 in storage and 1 that my son uses, a like-new 1991 black label that is totally stock, and at least 2 in parts waiting to be brought back to life. Then there are a couple of more carcasses of each, standard and M-122, in the "junk" pile.
Model Ms no longer have much appeal to me, I have used my near-ANSI modded Model F-122s constantly for a year and a half, and they are an order of magnitude more pleasant and enjoyable to use.
For less than $30 delivered, I might buy an M for the keycaps, but otherwise, I am pretty much over it.
If I ever find myself with energy to spare and a dozen hours of idle time, I might try to chop one of them down to some smaller footprint.