I am wondering if whoever did this didn't have those pickups made to fit the original pickup cavities. Those don't look like any P-90s I've ever seen. Some of you guys with some old-school experience chime in if you have, but these look like some custom jobs to me. It would sure be nice if somebody did not hack this one up.
Here is what a medium-scale Series Guitar looks like without pickups. It happens to be a 1978, made within a few numbers of this one.