I've been trying to source some wheel rubber for those larger wheels. I've been searching for bulk rolls for patio or garden carts. No luck so far. I should call the folks that restored my Seville to see if they might have any ideas.
I love the looks of the chariot cart. Nice find and restore you have there. Maybe ypu can get a long automotive fan belt to glue on the wheels so you can at least roll it. Awesome RRR!