All about Gruen

[Fred]

This caliber number is unknown to me. Stamped with US patent 833489 (Edward Staehli setting mechanism). Hunter case.
-Back marked “Wadsworth Referee Warranted 20 Years.”
-Front marked with case number 2,288,8XX
-Ceramic dial with Sub-Seconds signed “Premo”

[Dietrich]

Have seen this before and just out of the memory looks like a Degoumois movement. Unfortunately I am still quarantined without access to my regular computer and cannot look it up.

[thesnark]

For my part, I would suggest a hunter variation of Lavina caliber 63.

[Dietrich]

Hi,

good to see you here! And yes, you might be right with a Lavina origin. There are some elements which would point in that direction. I think a look under the dial would tell if it is really Lavina or not.