Need help with ID and value - to sell for client

[Peabo Felliwigg]

I have a short, 6'6" total length, 8 mounting holes, thickness at hub 4-1/2", 6 laminated layers, metal clad leading edge and tips are gray-green. The rear of the hub is 12" dia. The 3/8" high numbers are imprinted on the front of the hub - one side shows 66 X 450. The other side of the hub appears to be 386686 (or 380686 or similar); beneath that is DEB40F or DEB4QF (Althought the "B" could be an . The only history I could pry out of the client was, "It would be against protocol," and "crash of a US spy plane". Dubious. The pic is only half of the prop to better see the configuration of the metal cladding.

[Dave]

Likely "DES 40F", which might indicate a 40 HP Franklin engine, although that's probably a stretch. The 66 x 450 is most like the diameter (6', 6" and the pitch, which was often expressed as a fraction of feet, as in 4.5 feet.

The 6 digit numbers are more digits than I've seen as drawing numbers, so I don't know what they indicate.