I did a little bit of sleuthing to see if I could find any discussions or images sympathetic to my problem, and I came across the image below. Originally I grabbed this image because it gave me an indication of how the passenger side engine mount should work. BUT, I note now that there is a red line in this image (took me a bit to see it, I am red/green colour blind....) showing where the main brace had been cut away to
make room for the selector spindle!
It also shows that this transmission seems to be mounted a bit lower in the chassis than I have it. Which also confirms my need to lower about 10mm to clear the chassis rail.
It's all making more sense now.....
Lukeyson