There were a handful of transistors supposedly made specifically for MC carts - I believe up until the early eighties, but you might be right (the audiophile boom seemed to peak around the late '70s from what I've seen). Sanyo and Hitachi both offered devices that were claimed to be developed for this purpose. IIRC, Mackie used the Sanyo parts in one of their consoles. Well, say what you want about Mackie, but their consoles have never been noisy!
There's a Self-designed MC preamp that parallels the SB737 at the front end.
2SA872 - I seem to remember that off top of head.
Justin