An update on this project-I bought the one ton disc brake
kit from "thoroco" and will use that to deal with the scarcity of brake drums etc. Also will be getting the HO52 rear end from "triplet" for a swap with mine which gets my speed up and drum brakes with obtainable parts and it has a couple of non split rim wheels too. I'll try to get some photos as I go and then learn how to post them for anyone else who might be considering these changes. It's been great dealing with fellow bolters.