I pulled the window hardware from inside the door on a 71 Riv recently and when I looked at my 72, I notice in 71 the window hardware inside the door has a metal surround on the teflon piece that slides up and down the guider bar that hooks to the actual window. My 72 has a yellow looking (i'm' guessing teflon) piece in the same place. Anyone know which is better? I'm looking to put the best stuff on there and sell the rest.