I spent some time at the airport today trying to figure out a way to solve this problem. This is part of the tailwheel bracket on the Cessna 170. You can see that a bolt head has sheared off. I have no idea why it happened, it just did. So now I have to fix it. It is impossible to get my fingers or a wrench into the back side so I can install a new bolt. I was looking at the parts diagram and noticed that this particular assembly is supposed to be riveted in place in original construction. That got me thinking. I could punch the bolt body into the fuselage and use a Cherry Max rivet which is a pulled rivet. This is not your Ace Hardware pop rivet, it is a structural rivet commonly used where you can't get in to buck a driven rivet. The hard part is going to be fishing out the bolt with a magnet. I stopped by the local supply shop and they have the rivets that I need, so theoretically, I am in business. We will see.