I bought the LMC turnsignal lenses also and found the rivets to be too large a head. Found other drive rivets that have a smaller diameter head and they looked much better. The Foam cushions the lense from the impact and you just have to take your time and not try to kill the rivet, or you can damage the lense.........
just click on the arrows to advance to the next picture......Kieth
http://kieth.smugmug.com/Trucks/66-GMC/i-WTZF5KZ