Is there any risk of running a detonated headbutton and piston? Or is it worth getting a new headbutton. This motor was running great until I ran it out of fuel and the glowplug went. I decided to rebiuld it and noticed the headbutton and top of cylinder are insanely detonated up.

If the piston skirt and liner are not scratched or damaged then you can get away with it. You will loose some performance but the engine will run so long as the piston skirt and liner is not damaged. I've run plenty of engines like that over the years mainly in as practice or wet engines though not my primary race engines.

When you have an old glowplug, you can clamp the tip in a Dremel/drill/lathe and screw the button on. With the use of 1200 grit sandpaper spinning the button arround you can make the button as new again.

With the same sandpaper you can also make the piston smooth again.

An option, don't forget to check head clearance with tin-solder afterwards.

Nothing else is damaged in the motor, you cannot tell anything is wrong by looking at the side of the piston or the sleeve/rod/crank/bearings The sandpaper option is intriguing since I don’t need to purchase anything and I think I’ll be doing that when I have the time to