Another one of my faves as it goes, i like anything quirky and rarely seen on screen lol.
I dont think there is much out there at all, all i could say is the ball is maybe around the 8" mark and just detailed with a lot of styrene.
Ill bet there are a slew of kit donors on it, but its impossible to see, the barrel looks to have a lot of what seems to be K&S tubing around it.
I think if you go from the SAG book, and use screencap ref too, youll come up with a nice replica El loco!
lee