Quote Originally Posted by Madcap View Post
After studying the original photos
That photo above the left rivet looks peened, and not ground flush. After peening, it would be fairly easy to make them look perfect..chamfer the hole in the heat shield to leave enough meat on the rivet, then when you file it flush it will be perfectly round like the hole. much harder to prepare the inside, but would be need to be done no matter how you inserted the rivet. if the holes are aligned both sides, you could insert rod through one side to drive a tool against the inside of the other to create a recess. If not, then maybe some kind of pull through tool was used?

What does the inside of your original adapter look like? is the hole flush or chamfered on the inside? In your case I'd worry more about function then duplicating the original method. When you finish filing/sanding/grinding, the outside will look right no matter what direction the rivet goes.