Back in my machine shop days, I used a product called form-a-thread. It's basically a cement that forms threads.

you apply it to the bolt, thread it in the hole, and let it dry. Once cured, the bolt will unthread from the cement (a release agent is used on the bolt)

I didn't expect it to work, but it did...I was able to apply 35 ft-lbs to the bolt.

This may be the best fix if nothing else pans out.