Ward-Burton?
I've never really looked at them before. Rear locking lugs/threads? Interesting. The stock design and buttplate are very American.
https://www.americanrifleman.org/content/the-ward-burton-rifle-america-s-first-military-bolt-action/On the one hand, it's wild to think our first military bolt gun was in 1871. On the other, the Swiss Vetterli of 1869 and updated as the 69/71 was also a bolt gun, but also a repeater, with 12 rounds of 41 cal fun in the tube below the barrel. Of course, the Swiss ripped off Winchester's cartridge lifter mechanism and only didn't sued by Winchester because they didn't recognize foreign patents. So the repeating part of that rifle owes credit to a US design of 1866.