The RXF-M5 EVA pistol proved to be a little difficult, as it is only briefly seen in the movie.
Alien: director's cut shows Kane drawing it to close in on the Xenomorph egg, but in the theatre cut this isn't seen.
Weyland-Yutani originally used it among their security forces, but due to its inability to fire more than a
few shots before the battery died, most were disposed to the company's merchant fleet as protective sidearms.
However: with a little digging, I found that the same prop was used in Star Wars as the stormtrooper officer pistol.
This meant it was possible to get a 3D print of that pistol made unpainted and modify it to look alike.