EPISODE IV: A NEW HOPE
Used by: Dr. Evazan

"I have the death sentence on twelve systems."

Well one of them may have been from the film Alien because an almost identical gun to Dr. Evazan's blaster makes an appearance in the film. Where exactly we are unsure but there is no mistaking that it appears in the The Book of Alien book. It is very likely that this may even be the same exact prop due to the fact that 20th Century Fox footed the bill for both Star Wars: A New Hope and Alien and that both were filmed in England.  The Alien prop did change very slightly from Evazan's blaster.

Modified "Roger Christian Special"
(This particular prop is from the film Alien.)

Rexim-Favor 9mm Submachine Gun

The base gun for these props is a Rexim-Favor 9mm Submachine Gun. For the prop the rear stock was removed as well as the main barrel of the weapon and the magazine. Two scopes, the same type used on Chewbacca's Bowcaster and on Fett's EE-3 Blasters from ESB and ROTJ, were added to the top of the gun and something is filling the magazine receiver; probably a simple block of wood similar to that filling the magazine receivers on some of the BlasTech E-11's.