I haven't got around to taking pictures of Zeltic's kettle yet, but it is as described above, a coil that the pot is lifted onto. In Zeltic's case the pot is a small stainless coffee pot that holds two cup fulls of water. It'll boil in 6 seconds, but its best to take 12 seconds, otherwise the water jumps out of the pot! It is hidden out of sioght in the side of the boiler room, so looks aren't an issue.
If I were building a larger more permenant kettle that was on display, i'd be inclined to lag and clad it with varnished wooden strips and brass bands like a small boiler. The other option would be a stainless pot, but heated with a gas torch until it went either gold or copper in colour, neither of which would need polishing. Zeltic's cylinder cover is stainless, but heated until it went gold coloured. Unfortunately it got heated a little too much, so ended up colling to copper colour. Ever so often it gets wiped down with a damp rag, and almost 20 years after it was done, it still looks like copper, but has never been polished.
Daniel