Hey there, My first post here in the Longines forum! I wanted to present you my only Longines. Another so-called "Calatrava" Longines . Of course it is not a Calatrava but for now I do not have the reference of my piece. The serial number indicates that it was produced in 1935 (5'345'xxx). The movement and caseback serials exactly match. It is powered by a manual wound 12.68z caliber which seems to be the earliest version since it has the nice single "internal" case screw. The case is 32-32.5mm in "staybrite" stainless steel. The crown is unsigned and the hands are very nicely blued, I love them. At first I did not find any piece that looked like mine (the majority have a dial with an "horizontal" 9) on the internet. However, @Syrte has what it seems to be the exact same reference as mine! I found it in this post: https://omegaforums.net/threads/recent-acquisition-a-steel-longines-calatrava.16026/#post-1447010 Do you have more information to share regarding your very nice watch @Syrte ? On my side I asked Longines for an extract of the archives so I will be able to know more about my watch. By the way I find it amazing that Longines is providing this service for free when other manufactures like to add a quite substantial fee for the same service. I need to find a nice 15mm strap now as the one currently fitted is quite used and too large! Here are some pictures of my watch, hope you like it Thanks for reading and if you have any information to share about this reference please do it!