A bit of drift:
Henry Whitter wrote or co-wrote Wreck of The Old "Southern" 97 and recorded it a couple of years before Dahlhart covered it. Carson Robison played back up guitar to Dahlhart on The Prisoner Song and the Wreck Of The Old 97. Robison then composed The Wreck of The Number 9 which became another smash hit.
All of this before The Sons Of The Pioneers but these songs were more country than western.