Sat in the cab of EBT 15 till 2am one night in September 1981 with the EBT GM who was working as hostler that night as the regular was sick. He told me about the four hoppers the D&S got. He said it was difficult as some of the cars in best shape are buried in the middle of middle of the strings and they had no motive power to switch, so they had to take four that were on the outside. When the C&TS got theirs, not sure what the situation was.
The four on the D&S are in regular almost continuous service in the summer months.