i recently bought a mij 1996 jazzmaster guitar from ebay. the seller claimed it was all original, but when it arrived, i noticed the bridge pup didnt fit in the cover. plus the magnets are adjustable (like a p-90 pup). upon taking it out, i found it was a seymour duncan, but dont know anything about the model. i do know that it fits axactly into a p-90 cover that i had laying around. could you tell me what SD pickup this is?