They use the same hub and shell as a Model T Ford. You should be able to find them without too much difficulty, maybe one at a time. If they are 12" rims you might look at the agriculture industry for blank rim hoops and have them laced up.
The article says it was reportedly built to El Mirage.. Where ells would you run it, on the streets of LA? At a 100K the speculative history makes no sense and without true history is just another ice sculpture.