This is a tough one to make a call on. I can see some dies being little used that came out of the smaller depots so the wear could be minimal. Many of the dies I saw (mostly the Comos brand) were well used as after the passenger service was discontinued the agent or cashier continued to use the dater to receipt bills of ladings and other documents requiring the Mopac name, location and date. The one at Wichita was closely guarded by the chief clerk (locked up every evening) as every manager that saw it wanted it.

I can see too why someone would clean these as the dirt and ink residue would build up on the die making it a mess to handle in a collection. The few daters I bought came from railroaders so I at least know their origin.

A little change in subject. At the larger stations were there were multiple cashiers or ticket sellers each had their own die marked with a letter for auditing purposes.