I knew I had seen those exact markings somewhere else before, I just had to figure out where! I finally remembered whose collection it was in and made arrangements to look at it again. I finally got to see the arm last night. It has been altered to a half stock shotgun, but everything is there from the rear barrel band back to the butt plate. The markings are identical, although in much better condition and very clear. The "Crown & Scepter" marks are easily seen to be poor representations of authentic British Birmingham proof marks. All iron parts, hammer, lock plate, and barrel band are marked with a hardness test punch mark. The entire assemblage exhibits the absolute worst workmanship I have ever seen on an arm that proports to be of English manufacture! The tang screw is off center and angles so far forward that the shank is notched to allow the rear lock screw to pass through to the lock plate. This means you have to remove the rear lock screw first because the tang screw is locked in place by the notch! The front and rear lock screws won't interchange and the square eared lock screw washers are two entirely different sizes! There is an assembly number on both the bottom of the barrel and in the rear of the stock barrel channel of 153. Oddly, the lock has no markings on the interior whatsoever, not even the assembly number! But, the quality of the lock parts is very high! The exterior is marked in the same manner as the example shown above, with the "Tower" stamp very bold, and the "Crown" very weak. The only other part that looks to be up to British standards is the rear sight. Although, the leg of the ladder is properly marked "5,6,7,8," the "9" was omitted from the upper sight notch location, so even that isn't correct! The worst part is, I think I've seen something written on this in the not too distant past, but can I remember where......heck no! As I recall, and my memory could be entirely flawed here, I believe it was identified as being a product from continental Europe, quickly thrown together and sold to American buyers very early in the rush to arms who were looking for British P-53 rifle muskets, hence the 1862 date on these examples. We have to remember that there were a multitude of private party buyers in Europe purchasing for agents in America who would then resell arms to States, Militia units, etc. I wouldn't be afraid to bet that some of these private buyers could have been easily fooled early on.
Anyway, there's some more "food for thought". I'm sure the whole story is out there somewhere, and it is the things like this that keep us interested 150 years later!
J.