It appears to be a Cavalry Arms lower receiver...
Is is a 1911 in the waist band?
Looks like a Cold Steel in the pocket?
Pretty sure you're right. The original builder was Wayne from AR15Armory, a frequent contributor [and good guy] at AR15.com, aka *ARFcom* before he passed away. He's one of the Absent Comrades now, and is likely packing a similar yellow DeWalt AR in Valhalla; the Vikings said that as long as those still here told tales of a warrior's courage, or happy ways- or stupidity that got him killed- he'd remain in the Long Hall with others of his kind.
The circa-1998 Cav Arms lowers weren't all that loved for being stout, [brittle in cold weather, I snapped a white one in half once] but you could get them in a wild array of colors back around Y2K.
Is is a 1911 in the waist band?
Yep! See following pic, if I got the html right.
Looks like a Cold Steel in the pocket?
Think so. I believe Kate replaced it with an Ernie Emerson CQB folder a Christmas or two later. I like girls who prefer knives to other jewelry.