Obtained same day this week from different sources both 19J are 150,080 1925+ Ultra-thin D.Gruen and 485,761 1918 very-Verithin. The U.-T. may be as late as 1929. It was for sale until then. It was not much thinner than the Verithins and thicker than the 1924 originated Ultra-Verithin. The very-Verithin is a case name for the Verithins. This one here makes a thinner watch than the U-T with a Verithin movement. With similar cases the specially contracted 19j D. Gruen cost twice as much as the Gruen factory 19j adjusted Verithin. Not justified in my opinion then or even now.
Found in Gruen 1929 dealer catalog they were selling worldwide, not just in Canada and U.S. Had over 1000 dealers in Germany then. The cheaper grade Alpina watch (Gruen Guild) was for Germany. Thus a reason for the 4 differently named cheaper models without serial numbers and in 17 ligne Verithin size.