Firing Pin In Hammer Sharps & Hankins Carbines & Army Models 1861? 1862? Model

[Bruce Cobb 1723V]

My research says that these rare carbines and long and short rifles number less than 1500 are all 1861 types. I also know the serial numbers are intermixed between them because I own some and see them that way. Why are they called Sharps & Hankins when there was no such company until 1863? So what are they supposed to be called? It seems not to matter if the later 20,000 have a firing pin in frame models they still want to call these firing pin in hammer carbines / short rifles a 1862 model. Tell what you think.