Hello OFMembers. Last year I auctioned a watch, thinking it's Venus 216 caliber (small second version of 221, or chrono big date 211). I noticed that a date window is a bit smaller but didn't pay much attention. Now I am pretty surprised to see it's not Venus. I cannot see any signature. Any idea what could that be, please?

Venus has two discs that rotate against each other on the same level. Here "tens" disc has an aperture, and it rotates in front of the unit's disc. I have never seen this before. Any ideas? thank you, tomas

 

Here is the Venus Big Date perfectly visible.

 

It looks like a Unitas 6310 or some related movement.

Cool watch!

 

Thank you. I checked it, it seemed to be promising, but I didn't find anything on it. I will probably go and see my watchmaker. We will try to unstrip the dial to look for some markings on the movement.

 

If there are no markings, try to take a picture of the dial side without the calendar plate.

The setting mechanism design should be able to point us to the movement manufacturer of the base movement.

I'm betting that the calendar plate is the same as on the Venus 216.

 

I hoped I would get to the bone of it without disassembly.
My watchmaker comes back from holiday any day soon, and we will look inside.
Really curious what we find.

 

I finally got to my watchmaker to look under the dial.
There are no markings whatsoever. Any ideas, anyone? thank you