I'll have to dig out my two RR Heritage Trust books, "Rolls Royce and the Mustang" and "Rolls Royce Crecy", and have a look again because I can't remember. But P.1 I think was one of the Crecy concept V-Twins (there were six V-12 Crecys built and tested, but IIRC, twelve of the V-Twins). Then...