"Is this a Constellation?"
What a dial! Somehow it looks as if Omega had simply forgotten the print and the logo on one of their Constellations. In the past, it was common that large manufacturers purchased their parts from smaller manufacturers, which had specialized in a particular part. In case of overproduction, it was common that these parts were recycled and combined with other surplus parts to create a new movement.
This resulted in watches with a very high quality, as the parts were originally intended for the large manufacturers.
In early eras, many watches were not branded as they were not considered as lifestyle products, but a tool.This watch is from such an era. The high level of craftsmanship can be seen at the details on the dial and the quality of the casing. A truly unique high quality timepiece.