This is actually two questions...bear with me. When speaking in terms of diameter of most common sized tuner holes in a bass headstock...am I correct to understand that there are only 9/16 and 11/16? If there are more...are the previously mentioned the most common? I have several different basses and most have the original, large Fender type "elephant ear" tuners which are large. However I also have several which have considerably smaller tuner heads/holes. I was wondering if there are any major issues with enlarging the holes for tuning machines. I have a jazz bass with small holes and I would like to enlarge them to accept the larger machines. This is a traditional Fender type headstock and the bass is 34" scale. Any opinions?