I can't seem to find any reference to this using the historical fleet list of aircraft. I know June/July 1979 was the right time (my first flight on an airplane ever), but I can't remember the type of aircraft this was.
The original B737-200 seating configuration was for 90 seats, 5 abreast, 2 on left side & 3 on right side of the aisle & all aircraft had the table with club seating for 5, forward on the right side. After the '73 fuel crisis, seat pitch was reduced & another row of 4 seats was added at the rear for a total of 94 seats. After deregulation, Piedmont went to a 6 abreast configuration with new, smaller seats & no more club seats or table for a total of 118 seats. None of the other Piedmont aircraft ever had club seating.
This is my best recollection.