I think I got my first 10-speed, an American Eagle Custom in December 1971; I can't remember too much about it except it had Shimano Eagle derailleurs (or that's my recollection!) with shifters mounted at the stem. I think it was late Spring or early Summer of 1973 when I traded it in for a Nishiki Competition tourer (db cr-mo, Sugino Mighty crank, SunTour V-GT derailleurs, SunTour bar-ends, Dia-Compe center-pulls, Araya rims, Sunshine large-flange hubs). So the name change must've come sometime in 1972 or early 1973.
I'm thinking of selling the Nishiki Competition, by the way. The frame's always been too big for me (the fellow told me to buy as big a frame as I could handle, which turned out to be 25"--significantly bigger than the 59cm RB-2 that I ride now. I know it's not the kind of marque that's usually seen here on CR, but if anyone's interested in a 25" cr-mo touring frame, let me know. . . .