356B Wiper restoration

[leewiffen]

I've asked the question to PRS however whilst waiting I was wondering if anyone here had restored the wiper mechanism on their 356B?

Mine seems OK apart from needing the insert and circlip that holds the shaft to the rotating arm ( I have some photos on flickr https://www.flickr.com/photos/95118177@ ... 358623342/ ) The first two show the side where it is intact whereas the other shows the hole and ball joint. My query is the part that fits in the arm and allows the shaft to rotate around the ball joint it seems there is fitted a rubber grommet or some sort of fibre washer? Does anyone have any advice what to use or have used?

I can get a rubber grommet to fit but am not sure if this will be sufficiently sturdy long term. It is not shown as a spare on the Porsche parts list but is an integral part of the mechanism, however has anyone made up something to make this work?
Ta
Lee