Old RR songs certainly evoke thoughts from the great days... "Hey Jim, you better get out the rig" Horse drawn taxi?
I don't have my old Pennsy timetables handy so I don't know when the Congo (or Senator from Baaahston) would leave Penn Station but I'd suspect when "Chattanooga Choo Choo" was written in 1941 that it was "Leaving the PENNSYLVANIA station about quarter to four" pulled by relatively new GG1.
Those were the days... lucky we are recreating them in miniature.