On USA parts made USFA's the cylinder flutes are not as pointed as on Italian parts guns, the ejector shroud housing cam is longer on USA parts guns, the firing pin is cone shaped on USA parts guns, the front sight is the same thickness from top to bottom on USA parts guns (Government Series guns are the exception), when the loading gate is opened the little hole where the loading gate pivot post goes into the frame is a small triangle and not rectangular or square, and the loading gate pivot arm is thicker on USA parts guns. As I stated earlier good photos of those areas would help. There may be other things one could identify that would help but at the present I cannot think of them.

I do remember one other, the checkering on the hammer is cut and not cast I believe.

I am certainly no expert but those are the things I have learned to look for in an attempt to identify USA parts guns from Italian parts guns. Others here probably know other ways to identify them. Somewhere Yahoody posted a article with photos on some of the things I have mentioned but I have been unable to find it. Up in the thumbtack area of this forum is a post by Yahoody about the little hole that shows where the loading gate pivot post fits into the frame.

I finally saw the 1st picture since Imgur pics aren't showing up on my laptop. For some years now Uberti ships 1866s with a plastic film over the brass.  Make sure that film isn't still on it.

I been threatened by members of my Posse to Brasso my Henry.   By Gawd Woodrow thems fightin' words!

The "Holy Trinity" came together last week with the addition of a Uberti Henry Carbine in .45 Colt.
It will be fed .45 Schofield smokeless rounds as my main Wild Bunch rifle. 
In a pinch it will also double as a main-match rifle for CAS, as it will hold ten .45 Schofield BP cartridges, albeit with no room for a "gamer stick" then.

My first was a HEGE Uberti Iron Frame Henry Rifle in .44-40 back in 1994. 
It was intended for the 110 yard prone precision discipline in MLAIC.
So it was decked out with a tunnel front sight, a tang sight, military style sling swivels & sling,
and a patch-box in the stock to hold the tunnel sight inserts.
It served me well with open sights for CAS main-match from 1997.
Nowadays it's mostly used for the Lever-action Pistol-caliber Long range sidematch.

The second one was a Uberti Henry Military Rifle in .45 Colt back in 2010ish.
It was immediately put in service as a mainmatch rifle being fed .45 Schofield BP rounds.
I have never felt the need to upgrade to the "Improved" Henry or the later "Gun that won the West".
A humble HEGE Armi Sport / Chiappa Spencer Carbine in .45 Schofield has served as my back-up gun until the Henry Carbine now graces my gun cabinet.

Now, if only HRA or Uberti would get around to making a replica of the Volcanic Navy size pistol in .44 Russian with a factory-installed short-stroke kit so it could be fired Duelist style...? 

The "cool-factor" of a brace of Volcanics, a Henry & an 1887 Winchester would just be off the charts...! 

My unadorned 1860 as modified to shoot the Cowboy45Special"  , and there's room for 8 more rounds in the magazine!