Couple of points Stalag Luft IV - Mentioned - As fr as I can see no one possible name listed was confirmed at Stalag Luft IV
https://en.wikipedia.org/wiki/Stalag_Luft_IV
in Gross Tychow, Pomerania (now Tychowo, Poland).
Opened May 1944 - So it is possible that prisoners were transferred to this by place from other camps
the POW number is by camp - As can be seen lots of people had the same number -
Though likely American - cannot be 100% sure - Possibly Canadaian who moved to US after war or any other nationality - I accept majority of those at Stalag Luft IV were American