1970 Pittsburgh Pirates program vs Montreal Expos, the inaugural season of Three Rivers Stadium.
The program has the two original game tickets attached inside.
This was a late season doubleheader played on Sept 22 1970, with the Pirates ready to clinch the National League Eastern Division.
Program and tickets are in EX condition.  Program has a minor tear on back cover and 
is unscored but has three Pirates player's names penciled here:
Hernandez, Davalillo, Briles.  These players were not acquired until the 1971 season.
Probably just a Pirate fan updating the roster.