USA SUB series

Is there a decent resource online anywhere about the USA SUB series? I can’t really find out much about them other than the fact that they’re basically a StingRay Classic with a poplar body and weird paint job. I recently bought a used teal one to replace the StingRay that I had to sell to pay medical bills last year and I’ve been really surprised by how good of a bass it is and want to learn more about the series. It doesn’t seem like they were around very long and given how cheap they are on the used market it doesn’t seem like people realize what they are (maybe bc of brand confusion with the new Sterling SUB series?). The bottom line is I love this bass, maybe even more than the actual StingRay I had to sell, and would love to learn more about how they came about, how long they were made, and why they were discontinued, but haven’t been able to find much. Thanks!