Dick,
I won't burn my fingers on prop efficiency, because the thrust x speed relationship is a major factor, and like you said, the influence of the drag (airframe) behind the prop becomes quite large.
The Wright flyer prop was just shy of being as efficient as the modern Mejzlik, though on first sight it would not seem to be, because of it's shape.
You will never hear me say that one prop is more efficient than the other.