Eygo, ProMax, Wei-Ya..... all the same difference.
There's other re-branded versions of this sort of chassis out there as well, I just don't remember more off hand. Simply put it's an aftermarket replacement chassis. Typically ops didn't want to, or didn't know how to, repair their original chassis and opted for the cheaper replacement rather than getting a new original.
There may even be a label on that large gold heatsink on the bottom side that can't be seen in the pics.