Yep. Like I said, off brand parts.
If you dig deep, you’ll find that an awful lot of “off brand” stuff is the same as name brand stuff...without the mark-up. Forged recievers...upper and lower come from a limited number of forges. The one on an upper I got from J&T Distributing bears a Cerro Forge mark. A close inspection of some of the gun porn reveals the same mark on Remington and Rock River Arms rifles, to name a couple. Lewis Machine and Tool does an great deal of work that doesn’t get LMT plastered all over it.