Tom,
I do not own a griswold DO, but I have a Wagner DO with the same dimensions. I tried some of my 10" camp oven lids on it. A Lodge lid is just a hair to big, a BSR lid is to small, I did find a Camp Chef lid that fit tightly. That exhausts my supply of 10" lids. There are other ovens out there so to answer your question it is probably possible to find a lid. IMHO it might be better to buy yourself a camp oven which has legs so you can set it over the coals. People seem to want premium prices for lids alone. Start with a 12" as it will serve you the best for all around use.