Jon,
Over the last 25 years or so, I have been the bearer of bad news to a bunch of guys who took a gun dealers word for it that a Darne, or, Darne clone was far higher grade than it actually turned out to be. Usually, there is no actual work on these upgrades just the dealer saying the gun is something it isnt.
Gun number one is exhibit A. While he makes a half assed attempt with some weasel mouth claim about not knowing what the gun actually is, that didnt stop him from listing it with the number 19, a high grade Darne in the scheme of things. But, it isnt a V19, in fact, it isnt a Darne. It is a Francisque Darne, built in the factory started by Regis Darnes Son using older Regis Darne patents, and the gun has been restocked in American walnut, with a pistol grip, a cheek piece, and a white line pad. It was a model known as the Classique, probably the highest grade of the lower grade F. Darne models.
Id call the asking price, optimistic.

The second gun is listed as an R10. It is not. Again, it is not an actual Darne, and is not an R10. My humble opinion, worth every penny it cost, is that the clones take a hit, price wise, versus an actual Darne, often through no fault of their own. Quite often they are very good quality, but, the equivalent Actual Darne sells for a bit more. More than likely, the proofed action and barrels were sold to a gunmaker out the back door of the Darne factory, to be finished up and either given a name, or, more common, left anonymous.

I dont believe it takes all that much home work to come up with what you are actually selling, but, that would likely bring the realization that either of these guns is an also ran, and should be priced accordingly.

Jon, the whole American Collectable gun thing is something I dont completely grasp, and never got involved in. My model 1912 works OK, but, I think my Remington model 17 is a better gun. But, the pricing is always higher on the former.
No good reason that I can see for that.

Best,
Ted