Found a 1Lt. Elton B. Long, 508th FS/404th FG. Only 1 claim though, for a Me 109 damaged on 17 Dec. 1944, time 1120-1230 hours, location F-4040, Bonn area.
Source: Frank J. Olynyk,
USAAF (European Theater) Credits For the Destruction of Enemy Aircraft in Air-to-Air Combat World War 2.
According to the p47pilots.com website 1Lt. Elton B. Long was born 6 June 1921 in Springfield, IL. Nothing in the short bio to suggest he was a POW but the postwar stuff mentioned leads me to think it's the guy you're seeking.
http://p47pilots.com/P47-Pilots.cfm?...on%20B.%20Long