Below is a picture of one of the C&O Railbox boxcars.
It still looks like a normal railbox but the number has been painted over
with a non matching yellow and a C&O number applied.
How to make a C&O Railbox boxcar:
1. Accurail makes a good model of the Railbox boxcar. I purchased a set that was on sale and came with three cars.
2. Assembly is easy. Add the door, add the couplers, add the wheels.
3. The Accurail car doesn't come with an ACI card, so add yours right below the "X" as in the picture.
4. The trick here is to weather the car now, while it still has its Railbox lettering. Overspray the car with dark grey overall. Use some light tan on the lower 1/4 of the car. Put a nice wash of dark brown and dark grey on the roof.
5. Tape off a square around the RBOX numbers on the sides and ends. Paint CSX Yellow or another yellow that is a noticebly different shade.
6. Apply either decals or dry transfer numbers.
7. Overspray with clear flat to seal it and you are done.