You do not need the incorrectly designed "ultimate engine steady". The torque needs to be reacted ONLY in the same plane as the top steady, so the standard late bottom steady should be used. It will need its bracket welded into the front subframe front crossmember, although you could devise an alternative bolted bracket.
As for the magic wand, I have seen a completely straight one on an early car. I do not believe that many were built like that, but I may be wrong. It was Charlie Ross, part time goalkeeper of Stenhousemuir in the 1960s and our Latin teacher who had the Mini. He was about 6'6", so we thought we would have a good laugh when he tried to sit in it, but Minis had more headroom than we, as schoolkids, envisaged.
One common reason they often work badly is that the two knuckles with ball and socket on top of the diff housing often wear internally, and even more often come loose and wear their splines. I had to be towed home by my Old Man once when that happened and the van just would not get up a hill. I completely checked out the carburettor, distributor etc, and even had the head off to see where the power had gone (about an hours work, I had plenty of practice for other reasons and was young and fit), and finally found that it was only going into 3rd and 4th gears. As it was nearing the end of its useful life I just arc welded the offending knuckle to the splined shaft.