I thought at the time when I first saw this Gruen movement, that it looked suspiciously like a movement made by Durowe, a German maker associated with Laco. Ranfft didn’t show this movement by the Gruen calibre number 629ss. This morning, I went to the Ranfft images and checked out Durowe, to find the movement in this Gruen is actually a Durowe calibre 570! Durowe later became absorbed by Timex who wanted the Durowe battery powered movement for early Timex Electrics. This was in the early 1960s. So I suspect this Gruen is likely from the mid 1950s.
View attachment 1063755
Click to expand...