There were two lettering schemes used at different times, and I believe there were only two boxcars. #3219, and #3468.
In the mid 60's, these cars were painted with gold bodys, black trucks and hardware, and silver roofs.
The original lettering was pretty much unchanged from the original style, only black. The "flying" heralds were used.
By 1969, as I recall, the cars were painted using the same lettering style as on the Passenger Car letterboards, which is the same style adoped by the D&S.
E-mail me if you would like a b&w photo or two I took in about 1967. I can also scan a color photo I have of the second scheme, but since it's not my picture, I won't post it.
Mike Trent