Might be worth contacting Status - they've probably been asked the question before. Owning both a 'Ray and a P, a quick measurement makes the 'Ray pocket about 1/2 cm longer than the P but both measure 43cm (give or take) from the 12th to the G string bridge saddle. Pocket widths are about the same. However, even if the two could be made to match up, no guarantee that intonation, relief, playing height etc would come together - bit like putting a V8 into a Morris Minor - possible, but inadvisable :-)