Here's what I'm thinking as far as recessing the jack goes.
If I file the marked area, because of the curve of the body it isn't necessary to recess a circular area for at least the first depth because there is no wood there to remove (it curves away).
Hopefully getting something like:
(artists impression)
and further recessing might still only need filing across the body as the sides of the recessed area fall away with the curve of the body.
Feel free to point out any flaws in this plan.![]()