Omega makes it kind of easy to collect vintage watches. They have a great archive on their website, and for a relatively small fee they will also send you documentation of when a watch was produced and where the watch was sent from the factory.
First rule in buying vintage is questioning everything the seller says. Second is Google is your best friend. Finally sometimes you take calculated risks. The Conny is an example. I bought it December and the movement was in sh1tty shape (signs of rust) - the axel holding the balance had rusted and was in two pieces. But my local watch guy was able to repair it. It’s now extremely accurate. It’s a keeper.
I like modern movements, but I find that there’s something special with the size and quality of the older ones. I often wonder why watches today are so super sized.
Brother of OoO
Around a year later, after mostly alternating between my AW and my ~9mm Rado, I went back to the Nomos dealer and changed my mind, deciding how nice it was to wear a watch that didn't feel like a lump of metal. It's almost a lost art, making smaller and thinner movements at a reasonable price.