Super doopa artillery piece

I received the left hand artillery piece recently from Ebay for $75. Although it has been repainted and probably re-sprung I am told it is worth much more. Most importantly (joy of joys) it fires its plastic shell about seven feet. I believe that these used to have metal shells that could knock heads off metal toy soldiers. Mathew, at one stage used it to fire in place of the other heavy gun and it did better for accuracy than matchstick loaded guns. (He incapacitated one of my gun and killed a crewman). The breach loading mechanism is a a wonderful device. I never had either of these guns in my childhood but what  a place they would have had in my militaristic little heart! I'm sure they would have targeted massed ranks of Timpo WW2, knights, cowboys and Indians, not to mention the occasional pet.