I take it your rubber section has perished. When i had this exhaust i used a nylon spacer of similar size drilled all the way through and used a 6mm bolt with penny washers. I think I got it out of b&q or halfords.
gary
i take it its the end can you want to change, I thought it was the fixing bracket to the rear shock. Post the dimensions of the fixing points and I will see if its the same as the JL end can.
Gary