Mr. NHV, I'd like to think that when Chessie sought to acquire the Maine Central (that's what I think the Pan Am acquisition was mostly about), I think she had more in mind than whatever cars she could "snitch" from the CP-M's existing traffic base.
121 was into Greenville Jct. at 07:34 with 9833/8144, 53 mixed freight, 6 wells/12 containers, 8877 (DPU), 36 wells/80 containers, 13 empty autoracks.
[Edited at 12:57]
120 was into Greenville Jct. at 12:40 with 8812/9816, 24 wells/26 containers, 27 empty wells, 39 mixed freight.