rules and regs
You can get an instructor to teach you on a non school aircraft if you are an owner or part owner of that aircraft. both you and your instructor must however be members of a club, operate from a licenced airfield and have fire cover. The aircraft must normally have a public transport C of A. If you are an owner, this is I think you will find not the case. The problem is finding an instructor who is freelance and willing to do the training. A flying school won't be happy with one of there instructors moonlighting in a private aircraft.