Here is a Bofors walkaround of the piece we have at Moorabbin.
I vividly remember reading those black and white war comics as kid where the stout Australian troops at Tobruk were using Bofors 40mm guns to shoot down Jerry Stukas, and seeing war films filled with gun crews frantically cranking and peering through their sights to bring their gun to bear. You’d think the 40mm Bofors and the 20mm Oerlikon were the only AA defence the Allies had!