1Shouta said:
Or rather than having Vader & Palpy watch over Imperial Star Destroyers, you could make the Death Star look more complete, giving the impression that by the time Episode IV happens it's been complete for a while.

That just makes the problem worse as the Death Star is just about finished in ANH.

That would mean that they almost finished it and then Grand Moff-balled it for nearly a couple of decades.

If Ady goes for the 2 Death Stars in ROTJ idea we could see two being built at once (letting the audience in on the idea of a second Death Star being out there) only to find there were actually three of them, that might be cool.

Building three of them might take over twenty years.

That way you deliberately blow the secret of the theatrical ROTJ only to set the audience up for the new surprise.