I took on the task of restoring an old 321 for a forum member with the help of my watchmaker. All that is missing is a single part. It is called a "pusher stem for zero action", part number 321.1758a or even a 321.1758b If anyone has a drawer full of parts or damaged movements this would be most helpful. Of course I will pay you handsomely for the part and for the shipping and paypal fees as well. We just cant find this last part. See images and contact me if you have a source or if you have the part yourself. Thanks!!
Much thanks to member oddboy who found it for me on a foreign ebay site. Purchased it straight away. A million thanks..