But no, Moore was playing a Heritage not a Gibson.
(And there's still a lot of controversy about whether the Peter Green LP was factory reversed, or if the pickup had been repaired and the magnet accidentally reversed during the repair. The gray plastic pickup lead is pretty solid proof that the pickup had been disassembled and repaired at some point.)
Jol Dantzig (one of Hamer's founders) wrote an article for Premier Guitar where he said Gary Moore let him examine Greeny in '84 and that the wiring and pickup cover solder joints were untouched so the magnet must have been reversed when it was first built.
Jol's a respected guy and Premier Guitar has a pretty good reputation, so there's that.
But when Gibson examined it to make the replicas, the neck pickup had 2 wires (red and blue plastic) inside gray plastic sheathing. Not '50s single cloth covered center wire covered in braided metal, and nothing like Gibson has ever used.
Which fits with the repair stories that have been circulating since the '70s.
The basic story is the pickup stopped working. Peter took it to a local shop and the repairman determined that a coil wire had broken, so he disassembled it, rewound it, then mistakenly put the magnet in backwards when he reassembled it. He presumably changed the lead wire at the same time. (Maybe because it was easier to solder that to the coil wires, or maybe to make it easier to thread the wire back through the crowded wire channel.)
Some pickup winders have speculated that it was rewound with a different gauge of wire than stock. And it's unclear if the repair tech turned the pickup around so that the poles were closer to the bridge, or if that happened later.
Peter was never a gearhead, he was doing a lot of drugs, and then he had his breakdown/epiphany. He said he didn't recall anything ever being particularly special about that Les Paul, and I've never heard anything one way or the other from his bandmates about whether the guitar always sounded like that, or if it happened after a repair.
So there will probably never be an absolute answer. It's hard to believe that Jol wouldn't have noticed the gray plastic wire. But Greeny was famous by then, so it's hard to believe that the wire got changed after that without it being documented.
That story should inspire gearheads to try it. That or wiring it out of phase with a pull pot like I did to my 2011 LPS. The jury is still out whether magnetically out of phase sounds the same as electrically out of phase. It might make a teeny difference because one magnet might affect the other pickup, but it opens up worlds of tone either way. Pull pots are good because the guitar is exactly the same when the knob isn't pulled out. Use a CTS 500K long shaft pull pot if you do it, but be very careful not to break the little plastic strip that holds the lugs on the pot. If you want to bend them down, use 2 pairs of pliers, cause if you just bend them the lug will snap off. Or get a tech to do it. Its just replacing a knob, but the tiny grommet holes on the switch part of the pot are a bitch to solder to. I just used solid wire and made my own terminals to solder to. I had to go in thru the jack plate hole and pickup holes and the switch hole. Otherwise, that guitar is gorgeous.