One of the main problems with my wheel (and most older wheels) was that the foam had seperated from the internal steel core at the 10:00 position and could be rotated on the core like a motorcycle throttle. If left unaddressed, this defect would prove fatal to any attempt at a cosmetic restoration as the foam would turn and crack the outer surface.
What I ended up doing was performing surgury on the wheel. I used a razor and sliced through the foam on theback side, down to the metal core, and then filled the area with black weatherstrip adhesive. Once filled, I wrapped the repaired area tightly in masking tape and left it overnight to cure. The repair worked perfectly: no more turning foam.
(The in-progress photo didn't come out so here is a later photo with the incision marked in red)
