Thanks for posting these articles. I didn't realize King retired in January 1975. I am even more perplexed, and curious why she would have come back for the last regular Slims event in Philadelphia. I know she played the 4 woman special in Austin, because that was the kind of event that really showcased women's tennis. (And amazing that as a semi-retired player, she nearly won it, almost knocking off young #1 Chrissie. Then again, seeing how Clijsters, Henin, and Date can comeback these days and do so well after retiring, it shouldn't be so surprising what King did in 1975, and again in 1977.)
Do you know when King made the decision to play Wimbledon in 1975?
PS - I think the 1975 Slims circuit was the first time all the events were played indoors. Prior to '75, the circuit was somewhat split and played throughout the year. They consolidated it into an indoor circuit beginning in 1975.