Not sure if I'm posting this question in the right area even though I read the manual. Bare with me. I'm rebuilding my front brake shoe cylinders on a 1967 fj40. The pic below shows two cups: 1) fluted plastic, and 2) 1x5/16" rubber cup. I've purchased many of the rebuild kits on the web, but none of them have the rubber cup (they have other larger rubber cup parts, but not the one I need). I managed to piece together all parts necessary for the four cylinders except I need one more 1x5/16" rubber cup. Can anyone direct me to where I can purchase this rubber cup?