I have seen the old brown M1911 holsters dyed black too. During the Viet Nam era more pistols were issued, for example when the M79 40mm was issued
at one per squad, that man also was issued a M1911A1 and others were also issued the pistol. I think they were starting to use-up the old supply of holsters
that and the fact that leather did not last too well in Viet Nam