I got my rubber ring from Chevy’s of the 40’s. It came as a complete circle, the ends were already glued. Using the outside metal piece as a guide I drilled the screw holes. What I did find was that the holes had to be larger on the outside to allow the thread bosses to set into the rubber. Be very careful to tighten the bolts evenly. That outside piece is a zinc (pot metal) die-casting
