There was a group many years ago which helped ex-servicemen and deserving cases with assistance to gain a CAA licence. Unfortunately, I cannot remember their name, it was something like 'The Aviation Training Service' or something along similar lines. Perhaps there is someone in the training world who would know if these people are still operating and how they can be contacted.
Failing that, keep studying in your spare time, as ex-RAF you will probably find the legislation the hardest part, but it makes sense ----- eventually.
Good luck
JA