Okay SS255, looks like Eastern operated 2 AVP-ABE flights each way for many years or so.
From this Mar 2 1982 Eastern System timetable looks EA operated two AVP-ABE-ATL roundtrips.
http://www.departedflights.com/EA030282p100.html
http://www.departedflights.com/EA030282p2.html
And if you are still interested from EA's Sept 6 1972 System timetable
http://www.departedflights.com/EA090672p4.html
http://www.departedflights.com/EA090672p66.html
http://www.departedflights.com/EA090672p68.html
Looks like back in 72 one flight operated AVP-ABE-DCA-MIA and the other AVP-ABE-DCA ATL-SRQ.
Eastern's timetables never showed aircraft types but I am guessing a mix of DC-9-30 and 727-100, possibly 727-200.
The same website's Allegheny Timetable from March 1, 1971 shows no ABE-AVP service but hey folks, check out the equipment types in the lower left of the page, wow, is that a jet powered Oldsmobile?
http://www.departedflights.com/AL030171p2.html
But in this Oct 28, 1979 USAir timetable their is one ABE-AVP flight.
http://www.departedflights.com/AL102879p6.html
And in this Dec 2, 1992 USAir timetable their is one Commuter flight ABE-AVP.
http://www.departedflights.com/US120292p4.html
Some of you may think I am a geek but old airline timetables, OAG's and schedules are fascinating.
Cheers
LGA777