This is via a good hobby friend, Andrew Campbell.
'Random old school, and I mean *really* old school, miniatures discovery of the day.
Apparently there was a company called the Home Foundry Manufacturing Company back in the 30s, possibly through the 40s or later, which sold home casting kits for miniatures.
Most were historical (for casting toy soldiers), but at least one set dipped into the sci fi realm - a Flash Gordon home casting kit. Who knew that home casting of sci fi figures went back that far?'
The Flash Gordon serial debuted in 1936 so there were probably quite a lot of 'toys' out there at some point. IMDB has some more info on the serial here and, of course, YouTube has countless clips etc but you can see the entire first series here;