I have a problem with a Framus Jazz Bass. One of the tuner bushings was missing when I got it (used, for free). The tuners look like fender tuners, but the mounting holes are 13 mm in diameter, not 17.5 as "normal" holes are. I've been trying to find tuners that would fit (nearest match was Schaller M4 (12mm)), but haven't found anything. Should I enlarge the holes to fit Gotoh GB-7's, or should I order a custom made bushing?