A couple of things, as I see it (fwiw):
"Also, the punch was hit with such force that it skidded across the coin, thus obliterating the "Y" of HENRY when struck. Simple Physics..."
I am not clear on how this is simple, because (1) a copper coin is a lot softer than a gun barrel, and (2) there are extant examples of non-obliterated JJ Henry stampings which certainly would have mandated a greater degree of force on iron as opposed to soft copper and yet retain their "Y." Iron, in fact, usually requires multiple strikes to effect a proper stamp, so seemingly would be more prone to skidding and/or mis-strikes.
Also: like Professor Gordon, I would likewise be very interested in learning how this particular piece can be verified because it seems to me that this particular field would be quite ripe for fraud. I can guarantee you that there are numerous individuals currently working within the gunsmithing trade who could very easily pull off a copy of this and I also guarantee that it could quite easily be "aged" to fool anyone. This would be child's play comparative to the aging of an entire rifle.
It seems to me that verification most likely will simply consist of publication (after all, if it is published, it must be authentic...) and a few words by a recognized authority in an appropriate field. Following this, all it needs to do is change hands for a considerable sum one time, and there you have it. If someone will purchase it for xxx dollars, then someone else will desire it and probably be willing to pay yyy dollars. And they're off!
I don't necessarily intend this to come off as sarcastic, because while it probably does (a habit predicated by many years of working with 'fakes..'), I am genuinely interested in more information.