Though it may seem a bit toy-like, AHM's Flat Car with Boat Props or propellers is an interesting offering and may not be as far from prototype as you may think. While reading Gary Dolzall's "Diesels from Eddystone: The Story of Baldwin Locomotives," I came upon a picture of an early VO-660 diesel switcher in 1939 pulling a set of flat cars, each carrying boat propellers. The propellers were made by Baldwin and with some wood supports and wires, the AHM layout of the car and load isn't all that off this image.