Same thing happened to me in 1981 on the neck pickup on the real 1975 light ash J-Bass I had then. At that point Fender was out of its corporate head and a player couldn't get replacement parts. I also installed original DiMarzio Model J pickups, with "patent applied for" stickers on them. Today if that happened, I would send the pickup out to Lindy to be rewound, but with the same wire as the other pickup to retain the historical consistency. Unfortunately, I live in an area of the country where back then there were no luthiers. So when the frets wore out I sold the bass instead of getting a refret. Not to worry. I know who owns it, and can borrow it any time I need a real '70's J-bass tone.