if you don't want to spend on idler bearing conversion
there is a chance one of these will fit
dunno if it does but there is a chance
gets you to a position where idle arm movement is not restricted by the bush being bonded to inner and outer shells
which is half way there
NOLATHANE 41012 STEERING IDLER ARM BUSHES SUITS CHRYSLER VALIANT VC VE VF VG VH - HS Autoparts
dimensions here to help you to see if it will fit
https://www.repco.co.nz/parts-servi...t-steering-idler-bushing-kit-41012/p/A1044628
you could of course use a piece of Delrin and make a 2 piece one (top hat bushes) if you have access to a lathe and are willing to polish up the shell and inner of the rubber one you have
Dave