cover sketch can be found on http://themarvelageofcomics.tumblr.com/image/29717888917
Patsy Walker last appeared in Patsy Walker's Fashion Parade #1. Buzz Baxter is also from Patsy Walker.
Beast's fur turns blue/black as of this issue.
Story unofficially crosses over with Thor #207 and Justice League of America #103.
Sources for letters credit are The Official Marvel Index to the X-Men (Olshevsky 1987), The Official Marvel Index to the X-Men (Ward 1994), and Official Index to the Marvel Universe (Vandal et al. 2009).
Disputed inker credit--Mike Esposito per Steve Whitaker and Nick Caputo, Joe Sinnott per the original indexer and Sinnott's personal records. Caputo believes Sinnott's records are in error and the cover is likely a combination of Esposito and Frank Giacoia, who often worked together on covers.
Disputed inker credit--Frank Giacoia per Nick Caputo and Jim Starlin, Mike Esposito per Steve Whitaker. Erroneously credited to Joe Sinnott in Sinnott's record books. Jim Starlin believes he may have provided the cover layout for George Tuska.
Sources for letters credit are The Marvel Comics Index (Olshevsky 1981), The Official Marvel Index to the X-Men (Olshevsky 1987), The Official Marvel Index to the X-Men (Ward 1994), and Official Index to the X-Men (Vandal et al. 2009).
Covers to Amazing Spider-Man #92, Hulk #150, #161, Amazing Adventures #12-16, Marvel Team-Up #4