Stu-
Step 1) Read my post here:
http://weberkettleclub.com/forums/grilling-bbqing/a-new-implement-in-the-war-on-cooking/Step 2) Go to your local Fleet Farm. Buy the disk and a pair of horse-shoes.
Step 3) Scrounge a small square of steel to plug the center hole, and whatever you want to use for a base/legs. Now is when you want to grind all of the powder-coating off the disk. (Not a fun job)
Step 4) Take all of the supplies (already cleaned up and cut to fit) to a local welding shop and have it welded up. Even most muffler shops will do some welding for a 12-pack.
Step 5) Toss the whole works into the campfire to burn/season it. DONE!
It's ironic, we were just talking about the discada last night at an extended family gathering. My dad said, "You should start making these and selling them!" It's a good thought, but shipping would be a bear as they are HEAVY!
On a side-note... Since you are in Wisconsin, if you are near any farm/implement salvage yards, you could probably get disks pretty cheap and they wouldn't need the powder-coating ground off, but may need rust clean up.
Keep me posted if you need any help.....