Regarding POW records, I’m sure someone will be able to tell you if there is somewhere else to obtain specific POW information.
The only PoW record I found was at TNA under WO 416/*/* Someone at TNA might ba able to tell you how these are organised. It told me the place of capture, and traced his path round the camps until his final demise for uncertain reasons.
The other card I found was a death card, also under WO 416/*/*, following the loss of a Lancaster and its crew over Belgium. Apparently the Germans were very efficient in letting us know of people captured/killed etc [1]. They were more punctilious with RAF personnel apparently but I have no idea why.
[1] TNA, WO 162/204, War Office,
‘History of Prisoner of War Branch (London) (Cas P.W)’
