Actually, the grey cars were purchased in 1963 specifically for stone service between Bittinger, PA and Sparrows Point, bringing in limestone for fluxing at the steel mill. The grey load is the right color. They ran in dedicated trains daily, a service which continues under CSX, only with less handsome equipment. I have photos from as late as 1987-88 with the WM cars still in this use.
After Chessie the Knife wrecked everything, some of these cars were pressed into coal service, I have photos from 1989 somewhere of a few of them in a coal drag at Magnolia cutoff, so if you're of that "ilk" you could do a black load.
Lee
