T. CUSHMAN / H. HARDER Identification Help

[Doug G.]

Requesting information about gunmakers T. Cushman / H. Harder (town, state, time period) who made the pictured half stock rifle. The percussion lock and barrel are both stamped P&S Remington who manufactured under their names in 1843-45. The walnut stock has double cheek rests, identical on both sides including the inlay. I've checked books covering Pennsylvania, Ohio, Indiana, and Illinois with no luck. Hoping someone can check the Swinney volumes of NY gunmakers as the cheek rests are very similar Gardner (NY).  Jacob Harder (NY - PA) also made double cheek rests with matching inlays and had sons...but none with the initial, "H". Thanks in advance.