It was mentioned higher up the thread but the Boultbee Flight Academy is the only CAA approved Spitfire school in the world. They sell advanced training courses which include full briefings from highly experienced Spitfire display pilots (most of who are ex Military, test pilots, airline captains) and you fly Tiger Moth, Harvard then Spitfire. Check it out here...
Boultbee Flight Academy
As I say, fully CAA approved and legal!
3 Point