Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Yes,  Stoker did a really good write up on the history of the PM research Stirling #1 and its predecessors which I found very informative.

I think he has it that the Davies Charlton was the 1st of this design back in the 50's.

https://www.officeofsteamforum.com/general-discussion/solar-1-stirling-engine-and-its-various-iterations/

What I find somewhat interesting is the US importer was in Columbus, Ohio and the author of the book that accompanied the later engines from Solar Engines was also in Columbus, Ohio.  Wonder if there was a connection there?