Current mirror: is there a name for this NPN-PNP pair, and how does it work?
I think they are just composite NPN - (lateral) PNP. 

In the day (ca. 1970), the only real PNP transistors they could make with that bipolar process would have been lateral PNP types with miserably low hFE (maybe 1/10 of the NPNs).

This contemporary patent has some similar structures eg. Fig 5.