Adywan, here's a little extra thing to do with the 'gantry' / 'background' sequence -

In the recent 'duel' shot you previewed, the right-hand section that 'sticks out' from the side of the structure at the very end of the 'gantry', seems to be slightly too close to the rest of it, compared to all the other shots it features in....

The section I'm referring to is seen behind Luke when he steps onto the 'circular' section of the overall structure. It has a 'rocket-booster'-shaped 'cone' piece at the base of it, which wrongly overlaps the 'circular' section in the 'duel' shot. In all the other shots (such as the ones shown above), this 'cone' piece is instead positioned very close to the 'circular' section (with a very slight gap between them), and ends just very slightly below it. ('Freezing' the shot where Vader slices through the 3 'posts' is the best place to see this)

This is no biggie, but since it's a 'fixed-camera' shot, it might be a nice adjustment for you to make.