In such a case couldn't you just 'clock' the hole pattern around a bit? Either 60 degrees to remain symmetrical or just enough to find 'fresh wood'. The pan is round and should 'locate' in the same plane.....
Yes, you can flip the clamps over or rotate the pan to get fresh wood. The problem is, that base parts, which have been used over years are deformed and don't match the drilling jig any more. Without the drilling jig, it is harder than one might think. If you have a close look you can easily notice, that the holes are off center, the tubes are in the center. Just a small detail.
The drilling jig is very precise, the body has to go in there without too much pressure (wood cracks) nor too much play. I always machine the two cones of the bottom part at a certain degree of moisture and before drilling the 14 holes (classic vapman), I make sure the wooden bodies have the same level of moisture as when turned on the lathe. Myself, I never tried to drill these three holes with a hand drill only.
vapman