Dave,
Very nice indeed.
I personally think it will be a Stirling type of engine that will finally deliver the solution to fossil fuel powered engines. The Japanese already have a 'car' running on a Stirling, and they have already been proved in the third world that Stirlings running off sun power can be used very efficiently for pumping water and other such things, now if they could only get one to run off moon power.
I don't know if Dr Stirling ever envisioned that his theories and designs might just save the planet, but he does deserve a lot more recognition than he already has.
Stirlings have always fascinated me, but I have only ever built a low temperature one, and it did run, but that was disabled because my gorilla fingers fumbled and I dropped it. It now needs a rebuild.
I do have all the bits of materials in my storage area for a complete assault on all the Stirling types, just finding the time to do it is always the problem.
Maybe one day.........
John