The leather backed brushes with the US stamp on them--those are very post war.  Wartime brushes were wood backed boar bristles with a leather handle screwed in place.  We've offered brushes based upon several different surviving originals before, but this one is definitely the most interesting.  McMurray & Co. of Lansingburgh, New York was likely the most prolific wartime brush contractor, and this example of their work shows minor variations from the goverment specs--brass screws, brass washers instead of strips of leather, etc.  And we've replicated the various stamps from the original exactly.