Secondary sources can include the first 30 issues or so of the Marvel comic, the Holiday Special, up to five novels (the Star Wars: From the Adventures of Luke Skywalker, Splinter of a Mind's Eye, Han Solo at Star's End, Han Solo's Revenge and Han Solo and the Lost Legacy), the various toys available, The Story of Star Wars record, children's books adaptaions and the first four plotlines of the Russ Manning newspaper strips.
Given this material, what do we know about the Galaxy Far, Far Away back then that no longer holds true under present concepts of Star Wars canon? What is as-yet (for '79) undefined? What can we extrapolate? Here are a few initial thoughts:
- Luke, Leia and Vader are not related. Luke's father was a fellow named Tan Skywalker (per the first Sunday Russ Manning strip, IIRC). Tan used to form a chummy adventuring trio with his buddies Darth and Obi-Wan. Leia is a perfectly normal space princess from Alderann whose lineage is not in dispute. The big guy in the black helmet? It says Vader, Darth right on his birth certificate.
- Obi-Wan was an officer in the Clone Wars, leading Alderaanian forces. The Clone Wars are presumably more than one war against some clones. Here in the U.S. no one refers to the conflict in Viet Nam as the Poor Bastards Who Couldn't Get A Deferrment War, for chrissake. Anybody who can clone an army can presumably clone more than one person, so as a kid I assumed that the masterminds behind the clone forces (who were themselves undoubtedly clones) also had access to dopplegangers. Imagine young Obi-Wan fighting five clone Obi-Wans while a sixth clone is busy tricking the good guys via simple impersonation.
- Per the original novel the Emperor is a pathetic puppet figure, not a cackling Sith overlord. Real power rests with soulless Imperial bureaucrats like Grand Moff Tarkin.
- Speaking of Tarkin, he's a pretty arrogant guy. He assumed incorrectly that the Death Star was invulnerable. He also assumed that Vader was the last Jedi. How many more Jedi are lurking on the fringes of galactic society? Maybe after his brush with his old master Vader ends up spending a lot of time chasing down many different Jedi instead of Luke specifically. Vader as Witchfinder General.
- There's no reason to assume that the Jedi order was outlawed or disbanded in Kenobi's lifetime. Maybe the order was suppressed generations ago and he, Skywalker and Vader were among one of the relic sects keeping the flame alive. Maybe there is no Jedi Order. Maybe Jedi Knights are exactly like medieval knights: a warrior class sworn to various lords. Obi-Wan as a vassal of Leia's father? Maybe Jedi had a wide range of allegiances, agendas and abilties. Their martial training and religious devotion to the Force may be the only threads that unify them.
- Han shot first.