Is there an adjustment if one of the hood scoops is not entirely flush with the hood? Or do I need to re-place it? Thanks.

 

Check the underside of the hood. You can definitely wiggle them around a little and make some fine adjustments.

 

Yep, the vent is held on by eleven clips, my guess is one or two of those clips aren't fully pressed home (or maybe broken off).
Three across the back (wide) end, two on the front (skinny) end and three down each side towards the front end.
How do I know this?
Coz I have one in my hot little hand as I type, I bought a used but in near new condition pair for cheap on a Fleabay auction a few months ago as spares.