Somewhere on this forum in the past I had read discussion of some ST60 examples having U pickups, but I don’t think I’ve seen any where you could rule out a pickup swap.
Having the code for the body would resolve what the guitar is or isn’t.
^^ Wow, warranty card filled out with 1982 purchase date and serial # very much proving the plausibility of 136xx serials in 1982... that's kind of an important one, pretty hard evidence and all.