Outside patch
 

Has anyone ever done a patch on the outside of a bass top? I have a bass that has plastic wood filler applied to a deep and wide gouge on the outside of a spruce top. I would like to replace it with solid wood, but it could be difficult (but not impossible) to do correctly.

Is this a common repair and how much fun is it to do?

I doubt it would be much fun at all!

Is the bondo really causing a problem, or is the damage itself creating some structural issue? If it is just a cosmetic issue I'd be inclined to leave it alone, unless the bass is completely apart for restoration.