Quote Originally Posted by Simon Barden View Post
Someone will have drilled the earthing hole by hand, and when drilling anything at a very small angle, it is difficult to get the initial hole started, as the drill will want to skid off in all directions. The steep angle also means that the drill is likely to throw off splinters around the hole, which will probably have been simply pulled back and removed, making the hole entrance look rough.
It's difficult to see how it was drilled unless using a right angle drill bit attachment. There's no way the jack hole lines up with the bridge earth wire hole. Maybe it was done earlier on when glueing the layers to form the body as a guess?

You might be able to see the layers of timber below in the control cavity. Bridge earth wire hole is on the far right.

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