I believe this picture was from that race. I think Julie Millard might have taken it.
Brian Flanders states:
It was summer 1979 (I think, was cheering them on Commercial Street). Can’t remember month. That’s Peter Millard with my uncle Ken Flanders. Julie Millard in background cheering her brother and runner Wayne Clark on bicycle. Julie Millard states that the race was held 7 Oct 1979
Is this Pat McMahon the runner who was in Portland, Maine in 1970?