Many thanks for your most kind offer. Dave has already volunteered to help me out so I'm all set for the rear brackets - and I already have a front one. Your offer is much appreciated, though!
Hi Alan, if the brackets are triangular they usually bolt on, there should be three holes each side in the rear lower frame rail, the other type are usually riveted to the rear top rail and are L shaped.
Thanks so much for your reply. If you have a set of these brackets you don't need please consider selling them to me! They will certainly be neater than anything I'll be able to make. And yes, the brackets are exactly those shown in the pictures (above this post) although I'm sure there are some variants.... I'm at allanmatchless@yahoo.com.