I had one of those last shown. A really fine job mechanically but the(plastic/nylon?) blades were terrible, flexed like an old Kavan yellow nylon prop. Never had the courage to run it as I felt the blades would/could not take the strain. Also had a rather limited pitch range, max +7 inches from memory. Also looked rather too delicate to flick start the engine. Way open to correction here but I think Wolfgang Matt had one on his Model (Arrow??) at the F3a W/C in South Africa in 1979.Wish I still had it though. Paul.