Ed,
Rubber paint is sh!t, don't waste your money, we used to use it on our inflatable tubes when I use to build RIBS, (rescue boats)
I used the LLP technique a few years ago on my `62 Vespa Sportique, just to see if white walls looked good before buying some, white emulsion, lasted all summer, must have done 30 or 40 miles on them!!! (at at least 25 mph!)
I would rather do the emulsion than rubber paint, but you could try mixing a bit of pva wood glue in to aid adhesion and longevity.
NB. Lenny, does this experience get me on the R and D team for LLP?
Cheers
MM