Dont know much about them fancy plastic guns I suppose you might be able to use the slide for a trout line weight. LET THE FLAMMING BEGINE! Naw im just joking its just a magnet on the side of the slide!
you could probably mount the lantern centered in place of a rear sight so you don't mess up the weapon's balance. then either drill a peep in the base of the lantern or just get good at point shooting. if you can still lift it.