OK
I have not seen the rifles you refer to and honestly, even if I have I am not qualified to give a "expert" opinion.
With that said, and going back to the court reference, lets cross examine the evidence you have provided so far....
I found information/pictures on seven of his rifles which would have been built in the period 1777 (when he finished his apprenticeship) and 1821, the year of his death (which essentially predated the emergence of percussion rifles).
In this age, we are blessed by being able to view photos of arms we may never be able to see in real life. But for the builder and researcher, photographs leave a lot to be desired.
Some have the eye and are actually able to see what they are looking at. Others could look all day long, and never really see.
The great guns of this period were built with tricks of the eye in their construction. So a builder, not only needs to see, he needs to know what he is seeing and how he can replicate it.
There is no substitute for actually handling the real thing. A great example is John Phillip Beck. In photographs, his rifles look robust, maybe even heavy. Nearly all who have had the privilege to handle a Beck, have been surprised at how dainty, almost fragile they feel in the flesh.
Of the 7 rifles, only one (1) was not carved/engraved - the others were quite fancy and typical of (his style) as it progressed.
Can we be sure that this atypical rifle is really genuine?
Could this be a Re-stock where a gun stocker from a later or even the same period, restocked the rifle using some or most of the original parts, especially the signed barrel?
A good stocker or gunsmith would try to capture the original hand. Some were better than others and even life long experts will disagree on the authenticity of atypical pieces.
On an online museum there is a smoothbore with a
possible attribution to gunmaker John Moll. I do stress the possible attribution.
This gun has a Spanish musket barrel, built like a smooth rifle,has a provision for a bayonet and has some engraved hardware that look to be engraved by Moll.
here is a summary of the expert reveiws...
Stockwork crude compared to Moll, it looks to be a composite gun made with some parts maybe engraved by Moll.
Later restock of a Moll made gun.
This gun may be a war time made gun and since he served in the Continental Army, this very well could have been his personal gun.
Since we are are not sure of the gun, it should be accepted into the museum on it's on merit as a interesting piece with a note that this could possibly be attributed to Moll.
Did the "fancier" rifles tend to survive because they were fancy (and possibly more expensive in the first place) and better cared for?
My present opinion is this and it may change in the future...
Historically the rifle was not a a play pretty of the landed gentry. While the best makers undoubtedly had some wealthy customers during the Golden Age, the American longrifle was a poor to middling class frontier arm. Now when I say poor I'm not talking about the guy in the back alley with the tin cup. I'm talking about the frontiersman who spends a years pay on a rifle to enable him to have another years pay.
Maybe he is a middle son.
Maybe he is a farmer hunter.
Maybe he is an Indian.
So the culture thing comes up again, whats fancy and whats plain?
Why do the 19th Century plain Tennessee rifles exist at all, shouldn't they all be used up?
Why were some very "fancy" rifles literally rescued from wood piles, trash heaps and barns, shouldn't they have had a place of honor?
Why were some very plain guns kept as a treasured family jewel? I thought they were all used,up yet some exist.
So I still the think the survival rate is based on the the original production rate.