A dude won it at a Seymour Duncan show, in a box that says 59. The posts for the mounting screws are long as a SD 59, but it has two lines of screws and no slugs. The back plate does not say Seymour Duncan.
I couldn't find any pics, but there are so many descriptions backing up what Ed said. That's a mighty righteous pickup your bud won! Very old and veeery rare.
That makes sense, they were giving away MJ wired SDuncans at the SD meeting, or so I was told (I didn't go). The winner of this pup traded it for a normal 59 cause he didn't like the yellow colour!! The guy who has it now is a good custumer of mine so he'll be happy but my pal who traded it will not!