I keep my eye out for photos of postwar 25s just for fun. I figure they might be of interest even if they aren't combat birds and lack any fancy paint. Workhorses at this point I guess
The BD birds I believe were stationed at Vance AFB. The others at Amarillo Texas
According to fuselagecodes.com, the planes with the "number/U" would have been wartime trainers based at Pampa, Texas: http://www.fuselagecodes.com/id66.html
No info on the "OK" code, however.