Being that I don't know how to weld, I'd use JB weld to adhere another piece of metal under the holy area of the CP, then fill the button holes in the CP with bondoglass. Thoroughly scuff both surfaces with rough sandpaper to give the JB weld a foothold.
What do you have to sand/grind with? If you don't have the powertools to do that, stick to regular bondo. Bondoglass is a lot tougher and would take forever to sand by hand. If you use regular bondo, it will probably crack while drilling new holes and need to be touched up, but should be fine if covered by artwork.
JB weld can be grinded like metal, so you could use it to fill the holes if you have a grinder. That would be the strongest, but that amount of JB weld could get expensive.