From Paul on Patreon:
"I’ve always thought there were a lot of older guns that deserve to be reproduced, many of which could be really simple to manufacture. PSA is planning the release of their StG44 repro which is exciting. But why don’t we see this sort of thing more often. I suppose not everyone in the firearms community is going to want this sort of thing, but I think there are a lot of guns that would sell well enough to justify their reproduction."

Fundamentally, we don't see more reproduction firearms because they are actually a lot harder and more expensive to make than people would think, and the market for them is small than people would think. Re-engineering old firearms for new production is a really substantial project, and the original data required rarely exists. The guns must be cheap enough and reliable enough to attract modern buyers, which will often require compromises on authenticity - which immediately reduces the already-small pool of potential buyers.