US domestic rights
BBMB/ PTH
Was working for PAA at LHR those days (1961-1978) and well remember the approaches to the US-CAB for US domestic continuation rights for international pax's being continually rejected. Hence the eagerness for a domestic partner which would have given some revenue benefits.
SFO-JFK-CDG may have been possible but CDG-SFO would have resulted in the pax having to be dropped at JFK to take a domestic carrier JFK-SFO.
That accounted for the top dollar price for a domestic partner being paid for National, just before the 1973 fuel hikes.
This led eventually to selling off the seed corn (IHC-Intercontinental Hotels Corp) which always provided a revenue contribution and no doubt contributed, along with other circumstances, to PAA's demise.
DaveD