Beautiful resto. Stovers have always been my favorite. Have a 1916 model Y 2hp restored and a 1910 K 1hp in process--but it has been for a couple of years!
I am sure you are aware of this, but look on the exhaust side of engine, on the base between the crankshaft bearing and where the cyl casting drops downward; will be hidden behind the flywheel. There will be a raised area with numbers; this is the actual casting date of the engine base. Think Stover started this practice around 1921.