came across this today. Can't find it in Sala. Guessing it's a redial or plain old fake?! No ref on back and looks / feels like a chromed case....
Sala is very good, but does by no means cover each and every variant. One of the most common misconceptions is that people think the reference number and the dial/hands design has something to do with each other. The thing with UG is that the ref has to do with the movement inside and the case it is housed in. The dial and hands are variants on top of that which has no separate reference. The watch in your post is possibly a re-dial. It looks that way from your pictures. However the lack of a reference number might just have to do with polishing. Popping the caseback and taking pictures of the movement and caseback will give you more answers.
Case back and movement photos. Cal 285, looks genuine. The case back says Berthoud geneve Numbers : 6309 and 693189
So I would call it a Franken. Not a fake, but made up of various parts. Berthoud Geneve was a brand under which UG was marketed. I have never managed to fully understand in what circumstances or markets they used the Berthoud name, but Berthoud is the family name of one of the UG founders. I am actually wearing a 1937 ref 7066 Berthoud Geneve myself today. It has a cal 385 which is what you would expect to find in a Berthoud (same as 285, but normally found in "non UG" branded watches). The movement is also signed Berthoud.
Franken being case from Berthoud, but dial and movement from UG? But the dial also puzzles me, since it doesn't have any indication of "compur" or "uni-compax"....
Dial does look a bit odd, but I am not an expert on these. Uni-Compax would be the most likely? This one is my cal 281.