The only Morse I can find in Ohio is Christopher Morse of Painesville 1847 - 1853. In 1850 he had one employee.

Gardner lists two possibilities; Pennsylvania Rifle Works of Philadelphia, G Dunlap proprietor, date unknown but makers of percussion rifles

Pennsylvania State Gun Factory established in 1776 - 1778 which means if they made your gun it would have to be a converted flintlock.

cheers Doug