Beautiful job and quite the runner!
If you boiled-down the essence of all the great engines in Jensen's 80+ year history and combined them, this is what you would get. It has everything! A riveted boiler with a tube sight glass in a plain, black firebox. Dark blue painted cast iron bases for both engine and generator. A very well running #20 that effortlessly powers the generator with a spare pulley to power more. Everything sitting on a rustic-looking board with brass tag.
The improvements are subtle and tasteful: a brass plug that actually holds the chimney and a nice upgrade from the Hayco strain relief.
Super job!