I rebuilt a Quadrafire Classic Bay this year. It had been in a basement and hadn't been cleaned in a long time and had a lot of surface rust. I cleaned it with a wire brush and then used good old Naval Jelly to nutralize the corrosion. I painted it with high temp Rustoleum 'High Heat' spray designed for grills and barbecues. It came out quite good with a nice even finish. As someone else mentioned the finish is probably more matt than the original but it's not like you have a pair of them sitting next to each other for people to compare! I would clean up the inside and spray it black now because it probably has no protection. The outside you can do later when the weather is better. Nice little project, especially at the price.