I'm not into field gear but that was a no brainer and it's no wonder you thought it was a repop at first. Beautiful original condition! Great find.
A little note.. When WW2 started the BAR was still standard issue. Much of the left over WW1 surplus equipment was still around including BAR belts, which were re-issued but in modified form. The butt-cup and .45 mag pouch were usually deleted and replaced instead with a pair or regular magazine pouches which increased the available load to 12x30 round magazines. These modified belts can be identified by their mis-matched pockets and wide WW1 belt fasteners.