Ancienne Le Brassus
1583
Getting warm... here's a hint
Here's picture no 1. The Cal. 2120 movement (photo is a Stock AP media image):
This picture has 2 things that aren't present in the ad... (not referring to the 'jubilee' inscription)

Picture no 2: This is is getting right to the matter (and even here, what's missing here is also one of the 2 things missing in the add, and it's not the oscellating weight) (picture is owned by the Purist 'Foversta') ... this one gives it away.

Thanks for reading,
S
:)
By: Ancienne Le Brassus : November 17th, 2010-21:45
Yeah, It's the winding ratchet for when the watch is manually wound (there's this weird void right below the crown as you saw, and then as in the picture of the disassembled movement there's a gear that's connected to the automatic winding of the rotor. I...