Jim Sear, I wasn't sure what hardness to use on the ones I cast. The replacements were 60 duro. That's what I used. You can buy the cast urethane up to 90 duro. It's amazing how rock hard the old rubber stop bumps were when they dried out. Wish I could easily make the small metal plates that the rubber stops are mounted on. I could pour extras. I might "fake" the plates since the rubber mixtures have a short shelf life after you open them up. Also, I am not sure what the 3/4" hole's function is at the top of the rubber. It might have something to do with there mass production process. I put it in mine anyhow. That's what that metal mold is on top of the plaster mold in my pictures.

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A day without laughter is a day wasted- Charlie Chaplin
When wrestling a grizzly bear, you have to keep at it until the bear gets tired, not when you get tired.
1948 Chevy 2-Ton