The paint finish is actually quite impressive. There are a few dings on the C&O hopper that reveal a grey substrate. I am thinking this is "pot metal", not brass. I also think it is heavier than a brass piece.
On the C&O piece, there happen to be two coupler types, the fixed knuckle on one end, and a what I believe to be a pre-war Lionel latch type on the other end. They are interchangeable, as the couplers attach to a single screw at about 1/2 to 5/8 inch from the end panel. I think you might be able to see in the photo there are two posts (if not pins) cast into the frame that limit the radial movement of the coupler arm. In actuality, the user could attach any type of compatible coupler to these cars.
I've not disassembled, but I can see the dowel pins that Harold describes positioning the two halves together.
I looked up http://www.tcawestern.org/alexander.htm
I believe presently that these two pieces may be from the American Model Railroad Company. "The American Model Railway Company put out a 40 page catalog in 1939." These however are freight cars, not coaches. And as to my remarks above, they may well be aluminum, not pot metal.
Were they two rail at the time?
