It was made in 1918, so it won't be date code stamped and I also suspect not marked model 12 on the side.
Which model, serial? if after 1920 check the date code stamped on the barrel. Remington Society of America, Manufactured Date link has the details.
The made them from 48 - 62, they are date code stamped on the barrel, the location and chart is on the Remington Society of America.
Check the date code stamped on the barrel. Look for the manufactured date link on the Remington Society of America for details.
1925, It's date code stamped - check related links for information on the Remington Society of America
1925, It's date code stamped - check related links for information on the Remington Society of America
Late 1929 according to serial list, the barrel will be marked with date code. Check the Manufactured Date link on the Remington Society of America.
Manufactured 1922, will be date code (month/year) on barrel see related links for information on the Remington Society of America.
1928, it's date code stamped on the barrel, see related links for information on the Remington Society of America.
Almost certainly 1932, but all 34's are date code stamped (month/year), see related links.
1928 but verify the date code on the Remington Society of America here: http://remingtonsociety.com/rsa/questions/barrelcodes
52 years old