To me the best repair option would be with helicoils. This would create the least removal of metal and therefore minimal reduction of edge distance. All you do is drill out the existing holes not much more than the major thread diameter. Tap the holes to the pitch of the helicoil and insert it. The original bolt size will thread right in. They are just as strong as the original threads, and if the original metal is soft they help prevent galling or otherwise boogering them up when installing the bolts.
If you already know of these and how they work, I apologize. I'm feeling a little talkative today.