Audemars Piguet Automatic Tourbillon Cushion Case 18K RARE & IMPORTANT

Audemars Piguet 25643 Slim Automatic Tourbillon 25643BAO000301 25643BA O 0003 01, 18k yellow gold cushion form case with stepped bezel on a strap with a matching 18k yellow gold tang buckle, automatic AP caliber 2870 movement, one minute tourbillon cage made from titanium with mono-metallic compensation balance visible through dial aperature at 11 o'clock, hammer style automatic weight with AP initials visible through aperature at 6 o'clock, champagne sunburst pattern dial with applied round hour markers, the winding crown, case and crystal are all signed, sapphire crystal, solid caseback which also serves as the back plate of the movement with visible jewels, size: 28mm x 32mm, thickness: 5.5mm, Like New with Original Box and Papers that are stamped but undated. A rare and important watch from AP developed and produced in 1986.