RE: the NYS Rolling Block:
-- Were chambered in .50-70 Gov't.
--Had a feature that upon closing the block, the hammer automatically returned to the half cock notch from full cock. (IIRC, some rifles for USA/USN also had this feature.)
As for the rifle in question, the high arch hammer & the side swept block ear resemble those on a NYS militia rifle, but the calibre is wrong.
Then again, maybe it was re-barreled @ a later date by a previous owner.
Under license, the Springfield Armory made early USN & USA rolling block rifles (.50-70 & .45-70). The right side of the lock was stamped w/ the eagle, US Springfield, & date on 3 lines.
Remington made thousands of these rifles & some were often utilized by military schools, various state militias, foreign contracts, & over runs were sold to the public.
In the late 1950’s - early 1960’s I recall seeing surplus domestic & foreign Rolling Blocks for sale @ prices which today seemed to be very inexpensive prices. Conditions ranged from new to used & abused.
W/o actually handling/inspecting the rifle, hard to say what it is/was.
Reference book on the military Rollers:
“The Remington Military Rolling Block Rifle”, 3rd ed., by Geo. Lyman
www.buffaloarms.com/browse.cfm/4,1983.html