The Mexicans also flew P47s in the Pacific Theater in WW2, (Esquadron 201) and were similarly equipted by the US.
http://en.wikipedia.org/wiki/Escuadr%C3%B3n_201
Douglas, was Brazil issued the S&W .38 Special "Victory Model" pistol as well? Perhaps the smaller holster is meant for this pistol, as canvas rarely shrinks.