Klaus said:
Well, there is a 16-year gap between Ep III and Ep IV. QUOTE]
It's this gap which has made me wonder if ol' George is going to spring one more SW movie on us after Ep. 3.... sure, it would be 'out of sequence' with the others, but there's a lot to tell in it.... there's the initial victory by the rebels mentioned in the intro to Ep.4, the theft of the Death Star plans, Leia getting involved with the rebels.... it could make a pretty good movie....
The Death Star plans were stolen by Kyle Katarn (the mercenary that would become Jedi) in the first Dark Forces game by LucasArts.
Expanded Universe, but it's there...
As for the Maw Installation, in 16 years there's plenty of time for Tarkin to take the plans to the Maw and start trying to turn those blueprints into something more palpable. Including the Darksaber (a Death Star stripped down to just the big gun, looked like a lightsaber handle, but huuuuuge).