Yes, and I assume it's the Magnum Opus like ours. It has a toggle for service and operate. In service, the ball moves out of the way so the drain hole can be easily cleaned. The second toggle is for low, medium and high water depth after each flush. In the low position, not much water is used for flushing and refilling... like for dry camping. In the high position, each flush uses most of a gallon of water... like when parked in an RV park with FHUs (Full HookUps). The bowl is flushed by gently pushing down on the handle. Water can be added to the bowl by gently pulling up on the handle. These johns probably were expensive... even at the turn of the century!
