That reminds me of the strangest JS2 I ever saw, about 5-6 years ago in San Antonio, it had one Hag pickup and one later humbucker and it appeared to be factory original. A few years later Robert (Hornisse) mentioned having owned one like that. Since he's only about 90 miles up the road, I'd guess it's the same bass he owned.
Anyway, I'm glad you got this one.