More short stories backing up full-issue reprints (that often have a page or two of new, gap-filling or retconning material).
I kind of wish I’d re-read X-Men just reading the Classic versions–the new material and back-ups are fun.
Issue #15 is a focus on The Starjammers’ origin. Corsair is being held captive, and has flashbacks about his childhood, and is then rescued by Ch’od, Raza, and Hepzibah. Then #16 has Banshee’s pre-X-Men back story in a story with his brother, Black Tom.