It has been almost 9 years since I started this post, but I have a worthy update!
In 2022, Joel Silver, a Producer of Predator, sold several items via auction, including pieces from the Special Forces team members seen in Predator. Included in those items were Poncho's (Richard Chaves) Grenade Launcher Scabbard and the ugliest version of his Mulit-shot Grenade Launcher you have ever seen.
I missed the auction but have been in contact with the winner for a long time, finally bringing this piece into my collection. After buying it, I matched the scabbard (to at least two scenes) and the grenade launcher (to one scene). These are challenging matches, but I am convinced they match. The scabbard is matched by its creases and the position of the tape on the buckles over the shoulder straps.. The gun is matched by the poor trimming of the excess flashing, which matches beautifully to the film's opening shots.
The back half of the MGL is an extremely rough casting of an HK MP5 cut off just before the breach, with two thin aluminum pipes glued to it. One of the pipes goes into a filled PVC tube representing the barrel. The other is glued to a very rough casting of the foregrip. The bulk of the weapon's body is simulated by foam padding, painted black, and loosely wrapped with heavy gauge electrical wire to hold the padding in place. Some of the padding had disintegrated, so I have worked to replace it, but the core is still intact.
This is film-making at its best. It is quick and dirty. It is very low-quality, but it gets the job done and works well for the film. I love it!