King: FWIW, I used a piece of the thick bulb seal on the front of the lower rad mount aluminum where it meets the body and I used riv nuts to attach the aluminum plate to the lower rad. This is now a removable mount plate with a ~ friction fit to the front of the lower rad opening of the body. The rad is sung with no noticeable vibration (eliminated by the thick bulk seal) and no rivets are required (no holes into the body).
Good luck