Yeah, but far in the future, I'm still building T-nuts. I once read about a design for a steam-condesor engine running on liquid/gas ammonia and a low TD.
Ant
There are a few LTD Stirling plans out there, but be aware that they can be a little rough to get going and require attention to details. Some of the free plans leave a lot to your imagination.
While I never got it to run on the heat from my hand, it rockets along sitting on an ice pack. A single votive candle is too much heat for it.
I can recommend Jerry's design except for the plastic pillars he uses to separate the hot and cold sides and secure them. They work but are very fiddly. It's far easier to drill and tap directly into the plastic ring that forms the displacer chamber. A subsequent free form LTD has verified that assertion in practice.
Regardless of how it's done, miniscule leaks into the displacer chamber can prevent these flea power engines from running. On the model shown above I eliminated the problem by using a thin layer of Vaseline as a seal between the chamber wall and end caps.