East Hampton was home to a slew of companies making bells, particularly small bells of the type used for bicycle bells, dinner bells, rail crossing gong bells, and later, telephone ringer bells....
The company on yours is probably N.N. Hill Brass co, they are listed in the factory inspection reports in 1914 as a maker of Metal Bells & Toys. A mention in Machinery puts the founding after 1866..
The ad below is from 1898....