I can't answer the rubber bumper question off-hand - perhaps if you checked the PET katalog? Here are 2 more pics of the same part I posted. The ID might be 6mm. The bushing (there are 2) has a small lip or flange and they fell apart the minute I handled them. I think the PN is 901 423 253 00 M105 for a $2 bronze replacement - if we're talking abt the same part.
Mine is an 87 so some of the parts are different.
