I have not worked on any custom on the C&O side of things yet. I have been concentrating on B&O equipment so far. Here is the most unique piece of C&O equipment I have, the rest is out of the box H-5's and Berkshires and a Mikado that currently say PRR but is going to be painted are relettered shortly.
I guess I had never seen the Bachmanns before - without the C&O For Progress logo it means that these hoppers date back before the 1950's. These would fit in with pre-1950's steam operations as well as 1950's operations. The C&O For Progress logo was added in the 1950's, so my three-bay Micro Trains and Roundhouse hoppers with this logo won't get too much weathering. Thanks for posting the pic!
That's a Micro-Trains hopper, I think the decals were from Northeast Decals - unfortuneately I don't see them for sale anymore. They also made a set for C&O passenger cars.
I've got some Microscale decal sets (number 60-145). These are supposed to be good for hoppers from 1935 to 1956. I have some undecorated Atlas 90 ton hoppers, but they're a little more modern than my "main" layout theme of early 1950's. I guess they'll work out OK when I get out my GP30's, GP40's in Chessie System...
Here's a couple of shots I took of C&O's Double End door, Auto boxcar built in 1930 (Plate 37 of the C&O Historical Society Freight Car Equipment book)