While searching for the Falcon’s actual Engine grill detail, I happen across this wonderful map of Mos Eisley as drawn by John R. Mullaney. Although this looked like a ‘Where’s Waldo’ map, look carefully and you can see Sith ship here:
http://www.thetopdraw.com/view/images/uploads/mos-eisley_1362755195.jpg
But this one is from the copy of the Star Wars cutaway book.
http://static2.wikia.nocookie.net/__cb20110307194536/starwars/images/2/20/Mos_Eisley_map.jpg
Update: 2022 The original link is gone but after going to his Website again, this is a much better image:
