I have a set of elephant ear Schaller Rickenbacker logo tuners. The closest match i can find on the Schaller website is the "BM" series. What I can't find is any info on recommended maximum/minimum headstock thickness or hole sizes for the shaft or bushing. I tried a test hole for the bushing, and 1/2" diameter seems about right, I can hand-press the bushing into the hole. The tuner shaft is just under 3/8" diameter, so a 3/8" hole would probably work, but I don't know what the optimum amount of slop should be around the shaft. Does anyone out there have experience with these tuners? I am ready to cut my headstock to thickness, don't want to cut it too thick or thin. Based on what I can find online, Ric bass headstocks are approx. 5/8" thick. Thanks!