A Watch With a Secret?
This is a mid 1940s example of one of the big names in Swiss watchmaking; Girard Perregaux.

A very pleasant simple style, 37mm in diameter case, a nice size when the fashion was smaller (presumably the perception was that small meant more advanced technology) and a heavily gold plated case with a stainless steel back.
The movement is the GP 27 (rebadged AS 1130), basic, 17 jewel, non-shock proof but, large, movement, rugged and reliable.

What about its origin? I don’t really know, but here, I’ve done some detective work.
The AS 1130 is commonly referred to as the “Wehrmachtswerk” (army movement).
The German military of the era (of this watch) issued watches that met their specifications but didn’t seem to favour any particular brand. But, they did favour one movement, the AS 1130, the wehrmachtswerk.
Some 60 years earlier, 1879 in fact, the German emperor Kaiser Wilhelm I placed an order with Swiss watchmaker Constant Girard (of Girard Perregaux fame) for 2,000 wristwatches to outfit his naval officers. The watches, which were produced in 14k gold to avoid rust, would have been quite valuable, unique and well noted amongst the German military for decades to come. By WWII the Girard Perregaux brand would have been a favourite among high ranking German officers.
This particular watch was purchased by a local collector from an estate auction in Argentina and I, more recently, purchased it from him. Other items in that auction suggested that the estate was of someone of German origin. Remember, after the war a lot of high ranking German officers headed in the direction of Argentina!
So could this watch, from the mid-40s, popular with German officers, from Argentina with a Wehrmachtswerk movement have belonged to a fleeing Nazi?
All circumstantial, I know, but I think a good, plausible story.
Girard Perregaux is one of the great watchmakers of the world with some landmark innovations and a lineage that goes back to 1791.
Today, Girard Peregaux is among the most exclusive names in watches with only three outlets in Australasia, which I know of, and with a price tag that reflects the brand’s exclusivity.