I decided to try chrome vinyl wrap on the sliding window frame side pieces today as the original chrome is virtually gone.  I am quite pleased with the results.  I replaced the felt in one of the side peices and will do the other tomorrow.  I decided that as the new felt is self adhesive I would not use the built-in clips but just leave them flat on the rest of the windows.   This afternoon I continued fitting up the new window frame with Delrin blocks, ready for painting and final assembly.  Before I put it in the bus I will measure all the parts so the rest of the frames can be manufactured.