Walter,
Reason for my query on pay was this. I've hunted down WW2 RAF officer pay rates and found:
http://forum.keypublishing.com/showthread.php?112268-RAF-pay-in-WWII
This shows a table of RAF Officers' Pay in WWII, gives P/O as £237 pa, or £0.65 (13/-) pd and F/O as £274 pa (15/-)pd. And I've heard somewhere of a 11/10 pd for an "Acting P/O on probation", whatever that was, but can't give a reference.
I know that I was paid 13/6 pd as a Sgt-pilot in '42, and I think a F/Sgt got 15/6. It follows that, for the time that you were a POW until your Commission caught up with you, your NCO pay would be more than that which you were due as an officer. So you'd lose out at the start, but, as you say, your pay rolled up after that into a nice little nest-egg.
A related query, did your change of status mean a transfer from a Stalag to an Oflag or anything like that ? Wasn't there an important difference in the fact that an OR can be compelled to work for his captors, but an officer cannot, under the Geneva Convention ?
Danny.