Anthony,
The 1890 - 91 catalog states that these were supplied with a japanned rim. The 1895 - 96 catalog states the same thing.
Regarding the high-temperature paint, I guess it depends on what you want. I think spray paint is going to look a good bit different than real japanning. I don't know if you have looked into what a japanned finish is, but it is pretty thick in the liquid form and contains asphaltum. When a japanned piece is "stoved" or baked in an oven, the finish melts to some extent and becomes glassy. It is a lot of work, but for some people, like the old Stanley plane crowd, it is the only way to get a finish that looks like the original.
You can always try the high-temperature paint approach on something small like a cast iron ash tray and see how it turns out. If you don't like it, strip it off, and see if you can find some real japan to try.
Jeff