Well my friend offered to machine a pair for me out of Delrin or Oilite, so now I’m trying to track down dimensional data. Original construction appears to be sleeve with a stepped collar in the middle and square rubber o rings go on either end. McMaster-Carr part referenced above seems to substitute for rubber o rings when doubled up. Not sure why that construction is needed - just machine sleeve with OD, ID, depth?
Looks to me like 2~21mm length, 30mm ID, 33mm OD stepped up to 40mm OD for middle third, McMaster Carr O-rings go on 2x on each end. Tho why not just one piece of say Delrin. .002” press fit?
Edit: found dimensional info in this thread:
https://forums.pelicanparts.com/porsche-911-technical-forum/1140702-steering-rack-et-al-yet-again.html
But why is the OD stepped the way it is? If fabbing new it seems reasonable to just machine OD of ends of bushing to ID of available O-rings from McMaster-Carr.