Here's some great Ralph McQuarrie art that is undoubtedly from the B-Wings sequence that got cut when they couldn't properly composite the B-Wings. This one, meanwhile, is closer to what we got. Both taken from this site.
This claims to be a storyboard of Mon Calamari Cruisers bombarding the surface of DSII, taken from this site though the H in the corner suggest it's from ye olde StarWars.com.
disclaimer: all found using google images just now