Hmmm…

Matte painting and model don’t match because it’s a different trench.

…or…

Matte painting and model don’t match because it’s a movie.

By the way… It’s crazy to think that nearly everybody still thinks that the YT-1300 freighter that we first see in this shot:

…is the Millennium Falcon.

In fact if you watch that scene again you’ll notice that it is never referred to as such in the actual scene. A shoot out occurs where Han kills some Stormtroopers and then we see a long shot of a different YT-1300 freighter leaving Mos Eisley in this shot:

How do we know this? Because the unnamed ship in the hangar does not have the distinctive radar dish that we see in all other shots of the Falcon. I bet you never noticed it before but it’s as clear as day. Obviously Han and co did a quick switch of ships to put the Imperials off the scent.