When installing my gearbox, it threw up an interesting positional problem which I'll reference below.
I have a very early S1, 238G (Jan '77), it seems that all of the S1 before approx 350G had slightly different features, and hence, go together away from what the manual says.
The problem I had with the gearbox concerns its position in the car relative to the other components, most especially the engine mounts.
The vertical aluminium uprights on the gearbox are slightly shorter (top horizontal dimension) than a late S1 or early S2.
I have the new hanger kit from SJ as the ol