Well its been said a couple of times...but expecting a return on something you destroyed...well thats crazy. You should have called and complained "BEFORE" you tried your jury rigging.

Its not any more jury rigging than trying to cut the holes in the first place with the drill rig held by masking tape--thats jury rigging.

The shims are not going to be "weight" sensitive...they are just going to make sure the screw is true to the center of the hole. You making a mountain out of a mole hill. As long as the prop is centered on the holes so the balance of the prop is not off, the actual tightening of the screws is going to keep anything from moving.

The wood dowels sound like an even "dandier" solution though.