1941
With the serial number that you have provided,your Hi-Standard model E pistol was made by that firm in the year 1939.
1971
1934. A rather early pistol.
Go to the Ruger website, customer service, historical data, pistol, find your model, and there is a serial number/ year of production list.With the serial number that you provided,your Ruger standard model single six revolver was made in 1960.If you have a standard model automatic Mark I pistol,it was made in 1957.
1978
1958
Pre 1951
1949-1950.
Early 1934
SN does not have enough numbers.
Go to www.histandard.info There is information about manufacturing dates.
Charles Petty's book might have it.