a stirling that small might be a bit beyond scrapheap challenge.
I don't know. I've got one here where the transfer cylinder is made from a coke can, and the power cylinder is made from a milk bottle top.
however i see no reason a stirling could not pull a kva (hp ) or two off a domestic woodburner giving more than enough power to drive any hvac fans required. add one of elon's battery packs and the lights n pooter work.
heat and power on a household scale from wood is an attractive option for some situations.
as a scrap heap challenge creating a practical woodburner x stirling hybrid seems plausible at the 5 to 10 kg of logs, ie heart of a house, size.
proof of concept should be fairly easy but making it work in a way that isn't extreme steam punk in the middle of the house might need a bit of thought .
a nice bonus is the "waste" heat is right where you might need some low temp heat.
30 odd years ago i came across a scandinavian system of wood fuel open fire with powered hvac and heat exchanger built into a whole house system. it was very good at warming a house efficiently on a few sticks.
adding in the power side (with an excess of leccy and still using all the heat) would be the next gen.