For the period you will have to use higher magnification loupe (10X) and determine the position of two notches in .800 mark, as well as the size of the crown (see images bellow). If it`s 1937 - 1949 then it was made some time before WWII because I doubt they made silver beakers during or shortly after the war when the country was in chaos.
Regards
![Image](https://abload.de/img/19261937j2jcp.jpg)