USA Customs in 1989 - Had IBZ/USA pickups?

[SliderJeff]

Hey guys,

I just saw a guitar at a pawn show the other day and wanted to make sure I wasn't nuts. The sucker has a 6 digit serial number on the back with a "9" as the first digit... so I assume that that means a 1989 model. Anyway, it's got a USA Custom sticker on the headstock but none of my catalogs from that era had any mention of the USA Custom stuff. Did guitars from then come with the same PU config as the S540 and 550's were coming with at the time, i.e. F1, F2, C2? Is this maybe a Franken-Ibanez with a custom's neck slapped onto a 570 or 770 body with a fake serial?

Thanks,
Jeff