Got this old guitar with a totally smashed in side.
Here it is after I pulled out all the broken pieces and cut a nice clean “hole”:

I made some kerfing out of some mahogany and glued it in (The kerfing on the top
is the original salvaged from this guitar):

I found this piece of a side in my pile of miscellaneous broken guitar parts and it fit pretty close. I had to mess with it a bit to fit it better.

Here it is all glued up:

After de-clampping:

Ater a little sanding, filling and finishing… Good as new: