replica flanders risers squishy bushings

Does anyone make a replacement for the flanders type risers rubber bushings that are not so squishy. THEY LOOK GREAT! But the rubber is squeezing out. I know http://www.roadratroberts.com had an aluminum bushing with risers for $175.00. I would like to buy something in a hard nylon instead of aluminum and don't need the risers themselves.
Has anyone had contact with Roadrat lately? I tried the contact link on his web site but it no longer works.
F

I have seen bushings that appear to be Nylon or Teflon. I don't know their origin.