Cast Iron Stoves

I have accumulated several of the cast iron stoves or hotplates...one single and 3 of the two burners. A couple are in really good shape and good to go. The other ones I would like to restore to their original condition (like I do with skillets)

I would like to know the original condition these stoves/hotplates were sold in....were they painted or seasoned or japanned?

I believe they differ by model and maker. Japanning was common.