My 1896 house in PA still has the old radiators (28). The seven on the third floor are more plain - not the beautiful ornamental ones. They used to be heated by a large coal furnace which was converted to oil sometime in the 1950’s. The original system was convection, so the piles got larger (up to 10”) as they got closer to the furnace.. when it went to oil, they put in a circulator pump but kept the old pipes.
When I bought it in 1987 I got rid of the furnace and piping which was all covered with asbestos (what a project) and put in a Weil McClain gas burner woth 5 zones. The only iron pipes we left were the 3/4” near the radiators - the rest is copper tubing.
If I could afford it, I’d put on a new gas furnace as they are far more efficient now.
Some of those old radiators were really beautiful. I think I would have kept one around just for ‘decor’.
I’ve seen a couple of videos of people refurbishing old parlor stoves, and sometimes fitting them with electric fires.
Can’t find the best one I’ve seen right now, but here is another:
https://www.youtube.com/watch?v=73LS6C7VAE0