Percy's makes a tool also called Wheelrite for $89.95 from Summit.
Part number PHP-01201

I purchased the Wheelrite tool after seeing it displayed in a glass case at SEMA and I am really disappointed in it. I immediately bolted it to my '67 Camaro and tried to dial up a 12" wide wheel only to find out it only goes to 11" plus maybe another 1/4" if you stretch it a little. If you disassemble it and drill another hole, you can get almost 11 3/4" out of it, but not 12" Oh sure, you can go up to 30" (I believe) but who is going to run 30" x 11" wheels? I would rather pay more and get a tool that is more useful. The wire they supplied to get the shape of the tire won't even snap into the mounting holes without using pliers. It's overpriced at $29.95 let alone$89.95 Anybody want mine?

Perry,

I'll keep you posted as to what I can build one for. I should have the first one in a couple weeks. The first one is being done in spare time, but we are keeping track of hours after what I have seen in these posts. Stay tuned!

Yes, please do. By the looks of your design, it appears you can actually put the tire on your unit (if you had the tire) or go with the bent wire idea to simulate the tire shape. That would be the best of both worlds.