I'm not sure what's going on there. I've installed one of those vibratos on two of my guitars, and one I had to plug/redrill the stud mount holes, and the other I didn't. When you look it up, the Warmoth site says the bushing holes are drilled for 9mm, but the Schaller diagrams call for a 10mm hole. Yet, on the one I had to plug, the holes were too big, which is the opposite of what you'd expect.