Your Model 1915 Favorite is based on what's known as a "swinging block" action, one that drops the breechblock from a pivot point ahead of the rear end of the barrel. (It only looks like a falling block).
It looks like your rifle's SN - 8100.
In 1915, Stevens introduced a major change in the 1894 Favorite action.
The action is made slightly heavier, ofter referred to as the Heavy Favorite.
The other changes were to a flat top breechblock and to a coil mainspring from an often-breaking, flat mainspring.
The Model 1915 Favorites became the No.17. No.20, No.27, No.28, & No.29 - depending upon what type barrel and/or sights were factory installed.
The round barrel on your Favorite defines it as a No.17.
In 1920, when Savage started to take over the Stevens factory, "SVG" was stamped on the Favorites, as well.
There are NO serial number DOM records available for any Stevens firearms, because Stevens had a "catastrophic office fire", and "lost all records" just after WWI, when said records were subpeonaed by the US Congress in 1922, when Congress was investigating WWI war profiteering by Stevens.
Sooooo, YOUR Model 1915 Favorite No.17, SN 8100 was made between 1915 & 1920, most likely about 1916, as Stevens made thousands of them per year.
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