Steve -
I see you are in Columbia TN, which is pretty close to all the stuff up at Cold Springs. If there is an Academy Sports there, they sell a 14 inch replacement cooking grid for about $4. It is too small to fit on a Smokey Joe as a cooking grate but if you use a little bit longer bolts for your 2nd grate shelf on your Smoke Joe conversion, it'll work just fine for the second grate.
Just a suggestion - I've been using one of these as a second grate for my conversion for a while.
Pat