Yes Gentlemen,
I'm well aware that it's possible, the point I was making is that all previous attempts have concluded that it either isn't practical or the advantages are too small to warrant the additional, cost, difficulty, weight and complexity.
With regards Prouty's article, I can't give you the exact Reference of the top of my head, but it was published in the last 18mths in the AHS magazine Vertiflite and carried out a comparitive study on a Robinson R44, with (a) a normal rotor and (b) A Thrust compounded version with a propeller at the back. As I recalled the article concluded that the compounded version would require more power to do the same job. [I'll dig the article out and give you the specifics.]
CRAN