So all I have to do is make up a circular clamp round the body of the pump, like the one pictured in the fuel pump part of the Moss catalog, but evidently not available since it does not have a part number pointing to it. And then seal it up somehow, and bolt it to the bulkhead. For some reason I had thought there was something like a mounting bracket welded in on the later cars.
Seems simple in principle. I doubt if my metal bending skills are going to win much praise, though...
Are there any issues re mounting an SU pump vertically or horizontally or whatever?