The only thing that is new from what I see is it went from an A2 stock to a magpul PRS. Everything else was exactly as I sold it. All the way down to the scope and mount. I am going to call him today and talk about it. If he comes out with it, I am going to leave it at that. If he denies, I will out him, on here. I have done a significant amount of business with him and he has always done me right. Other then being a little high on his prices, I have never seen anything unethical from him. This is a first for me.
In all honesty I wouldn't get too worked up over the whole thing. You wouldn't want him to deny you business in the future but I understand where you're coming from with him selling it as "new". If he wants to claim it's his personal build... well, let him tell his lies and take everything he says in the future with a grain of salt.
When you talk to him I'd make it clear that you are upset with him selling a used gun as "new". IMO that's the biggest fault of the whole ordeal. If you feel it's necessary to tell him that you don't appreciate him taking the credit for your work, so be it, but unless you're in the shop every time someone takes a look at it he's just going to claim it's his anyways.
The only reason I'd post the name of the shop is to let everyone on here know that they may need to take a better look at the guns they buy from that shop. It's your choice to keep it private or public and everyone should respect your choice. It's your build and your issue. Had you not made a post about it noone would know anyhow.