Great to see you setting up a table here Jim .... glad you made it mate!
That first little Stirling is actually surprisingly capable for the small displacement that it has, and though it appears to be rather poorly, or at least cheaply made, it does the job pretty well and doesn't slow down all that much when you put the load on the genny. Pretty amazing for a scam booby prize ... as it were.
Flame-lickers definitely do tend to be very temperamental, but obviously you have that one running really well now, and it actually does look to be rather well made. It is truly too bad that you didn't get what you actually bought, but for a cost of nothing more than frustration and worry, this seems to be a pretty good bargain .... congratulations on that ..... many who get scammed don't come out nearly so well !