Gearhead wrote
One of the ways is to glue a piece of wood in place. You drill a pilot hole, say, 3mm. Then, you push a strong piece of string through (nylon at least, better kevlar). The end of it you pull out through the f-hole. You prepare a piece of mahogany with a similar hole in the middle and glue on one side. You push the string through this hole, too, from the glue side. A knot around a nail on the other side will enable you to pull the piece of wood back through the f-hole onto the inside of the side of the body in exactly the right place. Now all you need to do is pull hard for a couple of hours ?
If you leave the string long enough, it sticks out the f-hole and you can pull the whole contraption out again.
That was the plan. Thanks for taking care of the finer details GH!!
