I was thinking that at first. But the magnets on the pickup, even disconnected, have an effect on the strings. Definitely a different, more betterer, sound with it removed.
If I do turn it into a "II" (it's an idea I've had rolling around anyway, long before I started this project), I'll either fill/cover the hole (or more likely, have it done by someone competent in such things), or leave the ring and mock up a dummy pickup/cover, with nothing in it
Dunno, lots of other things to tinker with on this thing before that decision has to be made