I've seen many Naval Co. Model F-B and own one as well. All of those I've seen and inspected, which I'm were are original, have a series of marks on the muzzle face including the four-bladed "propeller" (USCG or Maritime Admin? inspection or proof mark?) and the seller does not mention such marks. In addition, the carriages of all the originals I've seen were welded steel and had a machined steel pivot pin as the primary connection between the barrel and carriage. Seller admits the elevation-setting pin is not original but this is the very least of this item's issues.
You notice in the seller's photos, not one shows the muzzle face from anything but a 90-degree side view, so it is impossible to check for markings in the photos. Happenstance? I don't think so.
Seller says: [quoteThe friction primer system is intact and all original (the tread is also free and greased on both parts). ] Well, well, that's interesting. The model F-B is relatively recent and came along many years after ALL U.S.-made L.T. guns began being made with percussion firing locks using .32 S&W (rimmed, not rimless) blackpowder blanks. The "friction primer system" if that's really what it is, is not anything original to a real Naval Co. Model F-B.
Many L.T. gun owners like to shoot their guns with original or same-as-original 17-pound projectiles and coiled lines. I've made at least one video showing some of them doing that. If this piece gets into the hands of one of those shooters, disaster could easily result since the fakes are made with the cheapest yellow metal the fakers can find, which will not have anything near the tensile strength required for a line gun firing 17-pound projectiles.
If I get time I'll ask the seller what if any marks are on the muzzle and I'll betcha there either aren't any or he won't answer. Also, presence of the muzzle marks does not ensure authenticity since I've seen at least one "bronze" L.T. gun which was a fake but had proper-looking muzzle marks applied. That particular one was a copy of the Galbraith bronze gun.
If in doubt, one other thing to check on a "bronze" L.T. gun is to look down the bore with a good flashlight such as a maglight or diode light. The bores on original bronze L.T. guns are "perfectly smooth" and perfectly cylindrical; the bores of fakes may show flaws or roughness, particularly toward the rear of the bore.
It sure seems to me that this is a fake and that the seller knows it is, ALTHOUGH of course for good legal reasons I am not stating as a fact that the seller is a crook, you should use your own judgment on that. But I hope if someone gets hurt, and I really hope no one does, that this post is still here at the time of the investigation as it will give those on the injured party's side a lot of help if they sue the seller for knowingly selling defective goods..