1950s Audemars Piquet rare Tonneau style movement Step design rectangular in 18K yellow gold

1950's Audemars Piguet 18kt Yellow Gold Step Design Rectangular Model with Rare Tonneau Movement, 4-position adjustment, Côtes de Genève and chamfering, beautiful and rare tonneau-shaped movement with huge sapphire sapphire sapphire crystal. The case with a sloping step design and the silver dial with different index lengths depending on the position make this seemingly simple rectangular model a unique gem with a lot of interesting and well-crafted details.