[Mart]

I've never done this, but did think about the inversion and how what we think of as normal would need to be done differently in this situation.

The cylinder needs to remain the right way up with the bleed nipple at the top, but be fitted at the bottom of the now upside down backplate.

I believe the circular register and the bolt holes on the back of the cylinder are not concentric with the bore so the holes in the backplate would need to be welded up and moved to put the centre line of the cylinder back where it should be.

The big end of the cylinder should point to the back. This would mean swapping cylinders left to right.
The long shoe should also be installed on the back.
Don't know about the grease retainer or the other problems associated with using hydraulics on an A but the things I listed above are what I believe to be right, but I've never seen them mentioned before (except by me).

Mart.