Maybe try a 2R? Things like 3R are different and couldn't comment on 18R at all.
Ebay dude - sometimes there's new old stock in the USA. Could also try a decent auto parts store like Bursons.
Also try Automotive Surplus here in Melbourne (they have store on Thornton Crescent Mitcham) - they have all sorts of old shit sitting on their shelves (like RS40 pitman arms!). I think they have (had?) a Sydney store as well.
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