Slow and steady, my bodge welds haven't ruined it, the MTX transmission is finally no longer swinging in the breeze.
There's a bit of movement in the bolt through the large-end of the bush - the bolt I have, and the OEM bolt, are both M14 - but the diameter of the bush itself seems to be m15.
I think in the final product I'd make the nut on the transmission-side bracket a welded captive nut as well, it's a bit of a gefinferpoken job to get it in there.
Lukeyson