James,
Welcome! The HO board could use a good swift kick . . . says the Nth degree inveterate N scaler! For Conrail of that period, you might look for articles in Model Railroader and Model Railroad Hobbyist (MRH) by Matt Snell. He's a prolific HO author, and he models Conrail in roughly your chosen period.
You should also check out the ConraiL Historical Society - many of its board members are TRW regulars.