I once owned a 1969 Chevy 1/2 ton pick-up with a step-side bed, that rusted out pretty badly. The bed was especially bad, and when I was done with it, it had more fiberglass and epoxy than a boat or a Corvette. The rear fenders actually both fell off at different times, and I used fiberglass cloth and epoxy to glue them back on. A little sanding and paint had her looking good again.
It was really great stuff that made a lasting repair. I drove that truck for 7 years and then sold it, with 186,000 miles on the odometer, for twice what I had paid for it. It was unusual that a truck of that vintage, with that many miles, still didn't burn oil, and had never been overhauled. Three guys were waiting for me when I came home, and I sold it to the first in line for my asking price. The guy didn't even want to take it for a test drive or hear it run. I shoulda' asked more for it, I guess.
That bubba repair was fine for a rusted out old work truck. For walnut gun stocks, I prefer Titebond II wood glue and more traditional methods.