Dan,
TMX butt stocks are pretty hard to find...
The good news is that the TMX and TM1 butt stocks are virtually identical. Because the TMX has a higher rib, TMX butt stocks have a slightly higher comb in order to keep the DAC (drop at comb) at about 1 3/8". A TM1 butt stock with a cheek pad or an adjustable comb is probably all you really need.
I have this OEM Monte Carlo set posted for sale: