This is a very difficult subject. There really is no proof, at least that everyone wants to accept, so there is a lot of "straw grasping" on both sides of the argument.
The half stocked Hawken is obviously a Americanized English sporting rifle.
But in the first 2 decades of the 19th Century there was a lot of confusion over just what a percussion system was going to be. Scent bottle, tube, pellet, etc etc.
We must also remember that the percussion cap while invented in 1814 or 1816 WAS IMPRACTICAL until it went through several "improvements" and was not patented until 1822. The copper cap we know of today being finally settled on somewhere in the 1816-1822 (?) time line. The first caps were reloadable iron according the Nigel George. Based on this then a percussion Hawken made by J&S in 1825 would be pretty darned early.
Then we have to ask how much did the patent interfere with the free use of the cap?
I was looking through George's "English Guns and Rifles" to see if I could find an early patent breech gun but the earliest I found using a percussion cap is the 1836 Brunswick.
It would have been wonderful if Jake & Sam had DATED a few guns. Like the "Petersen" Hawken.
But the scoundrels steadfastly (it seems) refused to date anything.
Frustrating.
So far as the late flint Hawken being made for a collector. Do we have any PERIOD reference to this? If it were for a collector and it was made in 1850 how is it that it has a broken wrist repaired with brass tacks and is converted to percussion? Not being all that well read I have not found anything from anyone in the 19th century stating that this rifle is one of a pair, as I have heard, or was ordered by a collector as seems to be popular today. Why would a collector want an example of a rifle a great many people insist was never made by J&S or S Hawken in the first place? And where would Sam get the PARTS in 1850 if they never made flintlocks?
So far as a script signed S Hawken Kentucky with no cut for the cock in the lock mortise this does not mean much. No way to prove where it was made or signed. The lack of the cock relief in the lock mortise is good indicator.
However... I would also point out that English flintlocks by around 1800-1810 did not ALL require a cut in the lock mortise since the cock stopped on the fence and the internal bridal, the cock did not touch the lock plate at all.
There is a John Manton double shotgun in its case with the lock removed pictured in George pg 215, Plate XIV. The stock has no cut what-so-ever for the flint cock.
This is not a determining factor in late flint era guns. Kinda like the bridal (or not) on a 1710 flintlock. And there were lots of English gun parts in the US by the time Sam moved to St Louis.
Locks for rifles going west were often stipulated to be "best" quality. Good English locks of the time were the best, period.
And while John Manton may have made locks in house its just and likely in fact MORE than likely John Manton BOUGHT locks from LOCK FILERS. These same lock filers also EXPORTED locks. True a lot of the low end stuff came to America it would seem. But that is not proof that the final evolution of the flintlock did not appear here in some numbers as well. Look at the S. North pistols in "Steel Canvas".
So we look at what was acceptable at the TIME. Flintlocks were the NORM in the west in 1830. This is not disputable. This fact in itself is PROOF that J&S had to make SOME flintlocks.
Full stocked rifles vs half stocked. The English were making 1/2 stocked rifles by 1800 that look REMARKABLY like a LATE Hawken from the rear of the lock forward.
Why apparently to the end of his career did Sam still make fullstocked rifles? BECAUSE SOME PEOPLE WANTED THEM.
Read "Firearms of the American West 1803-1865" until the end of the ML era there were both 1/2 and full stocked rifles being ordered for the western trade.
Some people liked FS guns.
To be so delusional as to think that in 1830 if someone came to Jake and Sam cash in hand stating he wanted one of their 1/2 stocked rifles with a flintlock and they would have turned him away is just ridiculous.
They were in the business of making and SELLING rifles and guns. Turning away customers is REALLY dumb.
I don't think Jake or Sam were such poor business men as to do this.
Remember "the customer is always right".
People did not often mention who made their rifle, at least not in the early years it would seem and seldom mentioned the ignition system but the mentions we have tell us that there were still flintlocks in use in the 1840s east and west.
The flintlock was still the norm into the 1830s so J&S had to make some simply to supply customers.
I am not the only one to come to this conclusion.
Dan