Here is a bit of a clearer idea as to what I may be able to help you with for the above mowes:
-Cowl, Tank, Starter, Muffler, Axels, Wheels and a referished carby, for the 1960's Self Propelled.
-A good grey cowl, and tank for the auto drive, and possibly a belt & Catcher.
-A cowl, replacement starter, tank, catcher, and carby for the vict amustang (Victa of fome sort, photo 6)
-An full engine, as well as axles, wheels, and maybe a catcher, for your mayfair deluxe base.
Looks like that trip to SA may well need to put on the cards at some point!!!