There are actually a couple of Kalashnikov USA's, and both are associated with the Saiga's.
I have one of the early Saigas converted by Marc Krebs (pre Krebs Custom) for the first, and now defunct Kalashnikov USA, out of Port St. Lucie FL.
If its one of their guns, its marked "Kalashnikov-USA Pt St Lucie FL" on the starboard side of the receiver, just below the ejection port.
These were early, and actually the first Saiga conversions done, back around the turn of the century.
The company sucked to deal with, and was at best shady (I dont believe Krebs had any association, other than building the guns for them), but the guns are, or were for the time, top notch (mine has been anyway). I had a second on order when they just up and disappeared.
$700 or so was what I paid then for my AK103K, which I still have and shoot pretty regularly. It was of the "ban" era, and has 14" barrel with a permanently attached brake.
Looks like this.....
My buddy got one from Krebs Custom a few years back, and his has a flash suppressor, which actually is the better choice. I keep threatening to send mine to him, and see if he would put one on mine. I believe he paid about $500 more for his gun, than I paid for mine.
$750 for one today, seems like a deal, if it was properly done.