you're right, here's more info ...
Text and picture from Christies
Patek Philippe. An extremely important and probably unique oversize chromed nickel splittable centre seconds aviator prototype wristwatch with Guillaume balance and black hour angle dial calibrated for 360°,
Signed Patek Philippe & Co., Genève, movement numbered twice 170'381, case no. 613'559, manufactured in 1936
Cal. 19''' nickel-finished lever movement numbered twice and stamped with the Geneva seal, 21 jewels, Guillaume balance with gold poising screws, swan neck regulator, wolf's tooth winding, black lacquer dial, engraved signature and scales, all filled with off-white varnish, outer luminous Arabic and baton five minute divisions, luminous hands, inner ring calibrated for 360 degrees, large circular case, downturned lugs, snap on back, splittable centre seconds operated through the crown, case, dial and movement signed
55.3 mm. diam.
and being rare means being expensive
This message has been edited by Bruno.M1 on 2009-04-13 14:11:03