It sounds to me like you have an original Varitone MK VI neck. If it is, and it is in good original condition, you might consider not messing with it at all until you at least get some idea of what it might be worth. The Selmers that were rigged up for the Varitone from the factory are RARE. A neck would likely be worth even more that a non-Varitone neck if you can imagine that with regular necks pushing $1K now. Sure, plenty of them were modified for the pickup including my 130491 neck but that was a fast experiment. The Varitone was kind of cool, but most guys didn't want to get saddled with carrying around the equivalent of a guitar amp plus the control box that was attached to the sax.
So, if you do remove the pickup, the tech will sweat it out and also remove the wire guide. He will make a plug out of sheet brass and round it like the neck. He will make it the same shape and size of the hole, then solder it in, finishing maybe with some sanding and polishing. You're going to lose some lacquer if it is an original Varitone neck because it was lacquered after all work was finished. This is why I suggest you NOT convert it if it is a real one. If the neck is a conversion, it probably was not relacquered.
Show some pictures when you get it and you will get some educated responses.