Possible. It's hard to tell from the distance, we have to rely on info from our Japanese friends. Those brands are very difficult to find outside of Japan.
Yes, and PGM is in fact a factory, they have their own brand but mostly they built for other companies like Van Zandt. They make LP for Combat but not for Van Zandt who make only fender models ( just like Moon used to next to their own models). Here's an interview of the boss
Deviser is another factory far from the PGM factory (PGM is in SAitama, Deviser in nagano,the next prefecture) they built Bacchus, Momose ( a star crafter from deviser) and Headways.
Deviser Own their own brand, PGM work for others. I think it's them who made the Ornetts for Kanda Shaokai ( Greco).