I don't think it is a lost art and definatly think it is do-able, the physics of hot water certainly haven't changed in the last 100 years. The question is are you willing to invest the money into a system that is slow to respond, that doesn't offer zone heat, and is expensive. Heating systems changed for a reason, the same reason we gave up the horse and buggy 100 years ago. The modern hydronic system is efficent, delivering heat when and where it is needed with little waste. If electricity is the issue then a gravity system would look attractive.
I have worked on many gravity systems over the years that were converted to circulator. The basement was full of three or four inch pipes covered with asbestous insulation. They didn't work good on circulators because of the amount of water in the pipes.
My own system started as a coal fired home made boiler that I fabricated from a cut off stove and a boiler welded out of plate welded to the stove. It started as a pure gravity system that we heated with for 5 years but I had to burn another stove in the back of the house. Wanting more centralized heat I replaced the home made rig with a Tarm wood boiler and converted to circulators. I retained the gravity section to use as a heat dump when the power fails. That system has run for 20 years now with no problems