there's a topic here on Talkbass in which users analyzed the live videos with close-ups on the bass and some pictures from the 70's, and it seems that he used the stock Fender flatwound, probably the 55-105 set there came stock in those days.
long silk over the saddles at the bridge, no silk at the headstock.
that's what most "vintage" player used without changing them, and what came stock on Fender basses up until 1983 (in the last years, probably mid 70's if I'm not wrong, they used the lighter gauge), when they dismissed flats and ashtrays and the basses came stock with rounds.
on his Jazz Bass he used them, also in the mid 70's, looking at live videos.
on other basses he used roundwounds, probably the Rotosound RS66, that were a standard for british musicians.