Re: PJ Marx 412 Pickup
As I said in a previous post, I've never really heard it. It came in an HM Strat that was wired up really bad. The person who wired it connected all of the mid points together (two humbucking singles and the PJ Marx) so that he could coil tap all three with one switch. Well, as you know inter-connecting all the pickups together at their midpoints is bound to create some odd tones.
I pulled the PJ Marx out, and installed a BKP Warpig I got for free with an ESP I bought at GC (it was included in the case). The warpig sounded great and has stayed in there.
The PJ Marx has sat in the parts box.
One other thing to mention - the mounting tab on my PJ Marx is NOT like the OP's pickup. It's not metal, it's the same resin the pickup is encased in, and only has one hole on either side. It was direct-mounted in the HM Strat so I don't think it had mounting threads.
The encasing of this pickup looks..."amaturish" so I'm guessing it was one of the early pickups. It looks like it was made in someone's basement.