The Aeronca C2 and C3 have remarkable performance for such low powered machines. I’ve flown several hundred hours in my C3 and have a C2 in the shop. The high aspect ratio wing is very efficient and the Aeronca E113 (or JAP J99 for an Englishman) provides honest horsepower at a sensible propeller speed. It might well only be 36 hp but is efficiently turned into thrust. The higher revving VW doesn’t provide the same efficiency. The suggestion of giving the Headwind a bigger wing is sensible as the original design is only 26 foot span; the Aeronca is 36 foot by comparison.