I purchased Skylark in November 2013 and worked on it out of the water all winter. Let me tell you it was a cold winter in Haverstraw. I started with an electric heater running off the Honda generator but I was miserable.
I found a used Wallas diesel heater on Ebay and set it up in the cockpit with the exhaust over the side and under the edge of the shrink wrap cover and the project became quite comfortable! After the propane box was finished I moved it into the quarter berth space. Unfortunately the exhaust hose that came with it was about 6 inches too short so I had to buy that too. Oh well….
Update: The Wallas 30D broke repeatedly with the power transistor that fires the glow plug failing. I fixed it a couple of times but it was damaged in the accident and I replaced it with a new Wallas 22DT. It’s a good size match for Skylark, it runs just fine and uses barely any fuel.