Sydney,

That Francotte reversed set trigger does require some extensive modifications - and also a pretty elaborate spring to make it work. It also has a very different sear arrangement when compared to the standard cadet - maybe I should try and find my parts pic I have somewhere...
FWIW, I also have BSA 12/15's converted to 22Hornet and 30-20, very nice - they maybe should get some new wood to do them justice...