In 1949 the Gruen Watch Co decided to produce an all American Watch with a USA made high grade movement this they called the 21 Series.These in good condition are getting much harder to find.
 
This Watch we date from around 1951, the case is made with a 10k Yellow gold filled bezel and a steel back, the case is in good condition, there a few scratches and dings but nothing that's detrimental to its looks, the silver dial shows only little sign of wear and the numerals are clear and visible through the Quattro faceted glass. 
Inside the case there is a 21 Jewel Lever movement signed Gruen Cincinnati USA.
Cosmetically overall this is somewhere between good and very good condition for its age and is running well.