I actually did a little internet research about the bell.
It is designed to the 1918 specifications of the U.S. Navy. So it probably dates from the 1920s or 1930s.
It is marked USN, because it was used on an unnamed vessel.
The length of the vessel, it was on, was between 26 and 65 feet, because the bell weighs 20 pounds.
I think, a Captain's Gig is a fair possibility for its use.