I recently picked up an aluminum jonboat cheap. The wood in the transom was rotten so it had to be replaced. To replace it I had to remove the two knee supports that are bolted through the transom an riveted through the bottom of the boat. Is there a method or source for re riveting these supports to the bottom? They are 3/16 X 1/4. I don't think pop rivets are the answer.Thanks in advance.