The early rotary valve Popes all ran Aussie-made carbies, as far as I know. Ours did, at any rate.
I'd say you're correct in picking it as an ESS; these would have only been fitted to 1950's-on Aussie-made engines, I'd expect. Our tariff barriers again!
It's an interesting question; apart from Victa and Pope, who else was manufacturing [not assembling, like Kirby] complete small engines in that era?
