Removed the tron disc motor assembly today, peeled off the black rubber, cleaned all the adhesive from the plastic then reassembled with the clear disc available from pinballcenter.eu.
I think it looks fine, discs are slightly taller than the plastic not flush, but didn't notice if the stock ones were flush either.
My disc wasn't perfectly cut out but pretty much close and a tight fit.
Hopefully this fixes any black rubber splatter on the playfield issues.