Some of you may recall I was sold a fake fender neck recently. The person has now told me to sell on the parts I was sold (there was also a body involved), and I think I might need some legal advice at some point.

This guy has called my girlfriend's phone, asking for "the rest" of the money (the other half we had agreed on when I initially agreed to buy it, but this was before knowing it was a fake).

He's now saying that "his brother is in the police force and he doesn't mind handing it over". Most likely an empty threat, but worrying anyway.

Let's say this goes down and he gets the police to intervene. How can he possibly have me convicted of anything? I do intend to sell the (legal) parts I received, and give him the rest of the money, purely because I just want this out of the way, but I won't be bullied like this.

What do I do?
It's a small claims issue. The police won't touch it. (The police can't touch it!) Call his bluff! Even if a cop shows up at your door, tell him that you know that he has no jurisdiction, get his name and badge #, and get his sorry ass fired! And then find the piece of garbage that sold you the fake neck, and shove it up his ass!
that's sort of what I was hoping to hear. I was just trying to buy a neck, I've done nothing wrong that I can see.
Police cant do... anythin at all there, that i can see. Unless you actually have a written agreement to pay him, you have no legal obligation to give him anything, really.
Dom, look... I Caught a PWOPER fish
I think I would be more worried if I were the seller. I mean, if you have any record (emails or whatever) showing that he intended to sell you a legitimate Fender neck, and what you received was a knockoff, he could get in a lot of trouble.

Obviously the guy is not too smart, otherwise he wouldn't try to fight with you. Sounds to me like you're in control here. I think I would tell him if he returned my money, I wouldn't report him for selling counterfeit parts.

Like you said, let him know you won't get bullied.
"Because hoes don't trust anyone.. especially me."