Actually... This is most likely a Model 12 made in early 1915, may not say model 12 on it and doesn't not have date code. I'm guessing if he didn't say model it's because it's not stamped on the side ;)
Please check the link for the Manufacture Date codes details on the Remington Society of America.
1920
1943
A link to the manufacture date tables by serial can be found on the Remington Society of America on this page. http://www.remingtonsociety.com/rsa/questions/barrelcodes 1942
Need to check the barrel date code. Remington Society of America, Manufacture date link has all the details.
Remington Works - 1914 (late)
Serial? 1909 to 1938ish From 1921 on they are date code stamped on the barrel. Check the Manufactured Date page on the Remington Society of America.
1912
1920
1924
1912
1912