I was making small talk with my FFL dealer while making an unrelated transfer and long story short, he tried to make me a deal I couldn't refuse. He offered me an Anderson AM10 lower for $50 NIB. How could I refuse that? I couldn't, I bought it. I got home, he had sold me a matched AM10 upper and lower with LPK. WTF? I had to call up the shop when I got home because I knew he had made a mistake. After he understood what he had done he said bring it back and get you $50 back, or keep it for dealer cost. What do I do??? What style of parts bolt on to an Anderson AM10 receiver? I've built AR15s but never AR10s. I don't want a hairy project with a bunch of mismatched parts, but a heavy hitting gas gun would be pretty cool. Your thoughts? Much thanks.