What should I do?

Lots of posts blaming the buyer on here. I mean yeah, you gotta do your due diligence but we tend to put more trust into people who have hundreds of posts and are a part of the community here.

If someone is a known member around here, I'm not going to ask him to do a Maxim photoshoot on every part sold because I trust that he's telling the truth.

99.999% of the blame is on the seller here. Misrepresented part that he knew was unusable trash and decided to stick someone with it anyway. You've got a responsibility as a seller to be honest and up front about the condition of the parts you're selling. You don't get to just be as vague as possible and then blame the buyer for not doing a ton of detective work to ensure you aren't selling a heap of trash or not.

"Uncle Tony" stuck me with a rusty spare tire well that was swiss cheese one time and then told me that "5 minutes with the welder" was all that was required to fix it. He knew I was replacing a rusty part and sold me a rusty part anyway. So he's trash to me, just like the seller of that dash.