Both Zenith and UG used Chronograph movements supplied by Martel hence the similarities. Eventually Zenith bought Martel and developed their own movements.
I am not speaking about movements parts 😀 The case is a UG-factory case with UG serial and reference number (you eventually could easily check it on Sala's book). The dial is basically a UG Compax dial, with the Zenith mark on it.
Inside there's a 156H movement and not a 285 of course. But the movement basis are the same.
I am new to watches, I picked this up. I've researched it, and all I know it has a 2572 movement, it was a 70s . I saw somewhere Zenith didn't always have model numbers or they went by movement numbers. Could this be the case here?
Something different today: 2 small size Zenith rectangular watches (same size with the original JLC Reverso) from the 30s-40s I believe. Just have it serviced, running at COSC spec now! Wow! That’s really something for these almost 100 years old watch.