I'm gonna have to break this down by the OT movies...
Hem Dazon, in Mos Eisley Cantina.
The Ice Cream Maker Guy, from Cloud City.
Sgt. Doallyn, from Jabba's Palace. He's the guy with the black helmet that Chewbacca tosses down Jabba's stairs. Luke bitch slaps him on the skiff, too, I think.