That's weird - when does that date from?
When I was a kid (in the 80's), my Mum bought me a 50's retro ray gun - it was chromed steel, with two translucent red plastic blisters on the sides, and the barrel was a separate articulated piece, so that when you pulled the trigger, the barrel would recoil, and the sparks from the caps would illuminate the plastic blisters - it was identical to that Batman gun (other than being a cap gun, rather than a water pistol, being silver metal, rather than blue plastic, and not having anything to do with Batman).
That Batman gun is from sometime in the mid 1960s.

