Very true Jeff, but the cross-tube is the piece that is most often affected by the rot-bug at its ends because of the poor design (re drainage), as you know, and it is an usual shape to boot! I think I read that the MGOC Workshop would weld one in 'in situ', if needs must.
If a ready fabricated solution were available, that would be a big step forward, I think. Mine is still perfectly OK, even after 350k kms., but I check it every time it goes up on the ramp, and I would put a cross-tube piece into the garage-stock if it were available, to join all the other "just in case" difficult and unique V8 parts, bushes, hoses, HEVAC and AC bits, steering, ECU etc. etc. 'Olive' is a keeper, and still a daily-drive car since "birth", so will probably out-survive me that way!
David