I had looked at Philip Arthur Boys-Stones just as Slipstream has. It seems he was starting his National Service in 1952, received a permanent commission in 1954 and retired in 1968.
However, the only UK birth for a P A Boys-Stones was registered in Leicester in the December quarter of 1928. This would surely have made him too young to have flown Catalina’s during the war. It would also have meant that he didn’t start his National Service until he was 24.
Regards,
kev35