Thanks Mike. Spent several days reading dozens of articles, PDFs, spec sheets and shortened my fingers at least a couple of mm googling all I could find on these key fobs but just got confused. On this forum I learnt more in an hour. Hmm!
Still, good to know I'm not the only insane tinkerer out there playing with stuff from China.
Purclewan
PS VERY jealous of your "shed". I collect old tractors and various cars, motorcycles and other things that move. Never have enough space or storage.