A copy of Dieter Marschall's book should help you. Probably 1931-33.
You will need to contact Walther
You will have to contact Walther to find out.
You will need to contact Walther.
1938
@1944
You will can contact Walther, but probably 1943-45.
Impossible to answer without the serial number.
You will have to call S&W to find out.
70-85
@ late 70's
Possibly late 30s
Roughly 1940-1945