OK there are some relevant and irrelevant variations here. Noting I do not have the rifle in hand.
Barrel looks pure Hawken. And since the rifle has provenance I doubt its been restamped.
The forend is very “Hawken”. Silver was not uncommon on the J&S rifles.
The brass BP and TG are a non-issue. But the buttplate has flats on the top which would be IMO a little off for a Hawken. But if it came down the river like that I cannot imagine it not being used OR if it was from a wrecked rifle someone traded in (who can say?). It should be round on top at this period I think. The TG is a lot like one on a heavy FS S Hawken in the Cody Museum. And there is a brass mounted scroll guard typical 1/2 stock “Rocky Mountain” rifle at Cody that is ALL brass mounted right down to the late design key escutcheons. So iron mounted is not set in stone.
Single trigger is a non-issue. Hawken “Rocky Mountain” rifles were made with single triggers.
Barrel, breech, standing breech all Hawken. OR much like what would have been used and it looks to be at least very late 1830s to 1840s to me. The breech is not the latest design. But its not mid-1830s either by the standing breech design. And there is a 1/2 stock in Cody with the later breech and the standing breech looks like that on what I am pretty sure is a mid-1830s rifle and the buttplate appears to be one of the cast versions. Remembering that they came, most likely, from Birmingham, just like the lock.
Back action lock is an oddity. Still it would take a lot less time to shape this rifle than it would the typical rifle with lock panels and also unless them came as a set fitting the lock to the breech takes time as well. The rifle would probably have saved 1/2 a day at least compared to a “standard” lock. But the wrist is weaker.
I do not like the way the comb is shaped where it blends to the wrist. But that big fullstock S hawken is a little big here as well just not that bad. And I am 100% SURE that this long heavy brass mounted S. Hawken “Kentucky” is pure Hawken. It has a cheekpiece detail that is identical to a FS S Hawken “Rocky Mountain Rifle” that we also had out of the case and hands on.
Patch box is just there it is what it is.
THEN…
In the 1840s when the Oregon and California migrations were running it was, according to a statement attributed to Sam, that they simply could not make enough guns at the time. Demand outstripped their capability. So they very well may not have been able to get anything but back action locks at some point or at least not enough “standard” locks. Or other classic “Hawken” parts. Remember that their supplies were coming down the Ohio by boat.
Looks like the hammer broke and was replaced by the local blacksmith.
Now it COULD be a restock. I still think the buttstock is a little crude. But there are some Hawkens that are not as carefully shaped as we might expect, cheekpieces come to mind.
Then the sling mount on the rod pipe but none on the stock. This concerns me a little. The Hawken shop would have put one on the stock I would think. But??? Did the pipe or pipe/rib assembly COME that way? Was it a salvage part? By the 1840s how much were they making in shop? I doubt they ever made the barrels other than reaming and rifling them. The breeches? Of course not. Locks were all bought from one supplier or another. We know they were buying from Tryon.
But then we have the CA Gold Rush/ Oregon migration thing so maybe things were rushed a little.
Keys in from the wrong side? Would have to see the barrel and stock separated. How many apprentices did Jake and Sam have in the shop? Did the customer want this or some later owner move them?
The fullstocked converted rifle that came from Cooper’s Landing, AK. At least thats where is was when it appeared in Baird’s book… As RAT has stated. Its not a Hawken. But I do not believe the marking is entirely spurious either. I think the barrel was rebreeched and probably freshed by the Hawken Shop and it probably was a good shooter and they stamped it. IIRC this is a pretty heavy rifle and may have been winning matches as a FL when it was converted. Probably post 1840. If this was the case and it was owned by someone that shot really well, they may well have put their name on it for advertising. They would not want people looking at a match winning rifle they reworked and ordering a Leman.