George is known for changing his gear quite frequently.
First he used a stock Duncan Distortion. Next he worked with SD on the Screamin' Demon, his first signature pickup. I think next it was the Super V, a signature pickup available from the SD Custom Shop. Then came the George Lynch Hunter, another signature available from the SD Custom Shop. ...and I probably missed one somewhere in the preceding.
If he is using the Arcane Pickups Mr. Scary, then he has moved away from SD. ...but it is George, he may very well be back to SD in the future.
Edit: So yes, I missed the Dokkenbucker, which was kind of a secret Custom Shop pickcup that George used between the stock DD and the Screamin' Demon.