I have a friend the US restoring one of these armored cars to operational status. He reports it is equipped with a 2 inch Bomb Thrower Mark 1. He believes it uses the same ammunition as the British 2 inch mortar. The bomb thrower is fitted to the turret with a fixed firing angle and fired from the inside. You adjust range with a valve that vents gas from the chamber. It has three settings, full vent, partial vent, closed. He believes it was only used to fire smoke rounds. Does anyone have a manual for this weapon? Does it use standard 2 inch mortar ammunition? Thank you in advance for your help.