I'm in a similar boat. I just put a new 6 gallon gas/electric Atwood in my rig. I got chrome paint at AutoZone. It looked really nice, but using LP it softened and lines formed in it. I had done five coats of chrome and three coats of clear.
Well I spent two hours tonight sanding it and I got most of it off. I picked up two cans of 1200 degree ceramic aluminum colored paint. That should fix it.
My old door is stainless and it looks fine. But, the new Atwood's have a larger grill than the old ones. It's not by much, but enough that it won't work. If I don't use the grill, my old door will mount right up. But, the new grill won't work with the old door. As well, the old one had the grill mounted to the exhaust and the door just had a hole in it; the new one has the grill mount to the door and it sets out a bit, so that furnace exhaust projects slightly out into the hole in the door. I can't see how to make the old one work.
Does the Roger Williams one fit the new water heaters with the larger hole and the grill that attaches to the door itself?