The American Performer pickguards Tone pot sits further up the channel....so the holes do not line up with regular Precision pickguards.The PG came from Warmoth. I got it with the Warmoth body and kept it when I returned the body,
The PG fit the body perfectly. Mounting holes and neck pocked lined up great. But there was one problem. The opening output jack hole (tone pot for me) was closer to the mounting screw the the Fender PG is. The Fender body didn't have a big enough opening to fit the tone pot so I had to route out more of the control cavity to get things to fit. So while Warmoth's PG fit great, I think the control holes are not drilled in exact Fender locations.
I drill an extra hole and put a sticker over the Precision bass jack hole....unless I use the original American Performer pickguard