[COLOR="DarkRed"]Bondo is nice for filling in sections of missing ply on interior or exterior.

Wood glue is good for regluing separating re-rings or plys.

Wood filler (plastic wood and the like) also works well for the Bondo-type jobs described above.

It works OK for smaller screw holes, too.

But for larger screw holes, I usually go with dowels...or...as the nice ol' cabinetmaker-guy around the corner showed me...chopsticks...which work great since they are tapered so they can fit a variety of hole sizes. Stick 'em in...push....secure...saw off the ends...sand.

For big holes (like old tom mount or spur mount holes), I actually use pieces of junk shells, cut out round... which I wedge into the offending opening, then seal with wood filler and sand.[/COLOR]

I'm a big fan of epoxy mixed with several additives to thicken. West System two part epoxy is great stuff. Nothing sticks better to wood and even metal. For large holes, the piece of old shell is a great idea. Look for West at marine stores or a good hardware store. They also have comprehensive manuals on how to use the stuff. I also use it with a small plastic syringe to inject into delaminated shells.