Thanks for the replies. I purchased this at a local, very reputable shop. 4473, NICS check and all. It was call traced through local PD when the shop brought it in to verify it at least currently isn't on any "hot" list.
There are no assembly numbers on any other part, and the butt looks to be original, not cut down. As well comparing it measurement wise to my other round butt, doesn't look like it was "altered", as in had the original SerNo milled off, or filed for that matter, all the profiles are the same. No other marks besides the model number under the crane(which matches factory mark), and the US on back strap.
Cash wise I've very little into it. I bought it as a parts donor/project piece to practice gunsmithing and refinishing on. Shame to have to cut it up, it's a wonderfully smooth and very accurate shooter.
Edit... I found that number stamped inside the side plate, don't know why I hadn't looked there before. So it looks like someone copied the assembly number?