Looks good Rick.
Having a flat-cut drill bit of a good diameter to fit the punch hole and using a stop like that would be awesome. 
Maybe an endmill or old straight router bit (finding the right diameter will be tough).

I like to have the center cleared out before the punch, gives the waste somewhere to go with the wedge chisel shape to avoid it scooting slightly back over the exposed wood. Of course small bites work too!