I seem to remember back in the mid 60's they had something called "porta walls". Essentially they were a flat ring of rubber with the whitewall and a rubber bead mount. You mounted them with your tire and the whitewall would lay against your black tire. They rarely laid against the black tire very well though. They were for folks who couldn't afford to buy whitewalls.
I don't remember if they had wide whitewall versions of it though.
Just some trivia.
