I believe the original bushes for the rear lower wishbone outer pivot pin were a DU bearing, which is supposed to be self-lubricating.
https://www.ggbearings.com/en/products/metal-polymer/du
I stand to be corrected by Dan!
I know of some folk with Cobras and Aces in Europe who have machined Vesconite to do the job instead, with some success:
https://www.vesconite.com/prod/hilube.htm
Its origins are in the mining industry, I believe.