Underhammer pinfire :Fingers may have been hot!
Joseph Dumonthier, gendarme, born around 1750, Epizon Haute Marne.
Joseph Celestin Dumonthier , cutler / gunsmith born in 1797 in Houdan
Celestin Dumonthier, gunsmith, born in 1821 in Houdan.
They definitely were not imaginative with names back then!
Jean Baptise Marie Guy is the brother of Joseph Celestin … and so son of Joseph Dumonthier