Pretty sure I know what I have

[Major 2]

But looking hedge my bet... or get a better skinny on the Mills H buckles.

Opinions ?

[Drydock]

The 1st one is an aftermarket item.  But the 2nd one . . . ah, we can only hope.

According to Stephen Dorsey's "American Military Belts and Related Equipments"  That appears to be the Model 1880 plate, the 1st and rarest of the "H" plates.  It is described as "A two piece sand cast plate, with a raised US on an oval recess.  All raised features were polished after casting."  The accompanying picture matchs your plate.

It would take an hands on expert to determine if it is the actual item, but it surely looks like it.

[Major 2]

Bingo on the 2nd one, it along with this one was dug at Fort Clark TX. in 1985
the Keeper is not the original one, but was found elsewhere...
The roller is missing on the plate....

the 7 w/ Cross Sabers was on a table at gun show ....I think it's a State plate

it is marked " Military Arms , Equipment and Ordnance Stores
                              M . Hartley Co.
                          312 & 315 Broadway
                              New York, NY

[Drydock]

Sorry, the 7th is a well known if well done fake.  But it surely sounds like the other two are for real!  That looks like an 1851 sabre belt plate, sans the nickle wreath.  Congrats on a rare find.

[Major 2]

The 7 X sabers was listed in ....
Hartley, M. Company Arms and Ammu. 1902 Catalog
| M. Hartley Company - Arms and Ammunition 1902 Catalog.

I never thought it was 7th.  Cavalry.... I don't recall what I paid for it    maybe $10 , I've had it 30 years or so.
I had Dog face Shogun Plate, but I haven't found it

http://www.ebay.com/itm/US-CAVALRY-Buckle-Anson-New-Brass-WITH-ANTIQUED-STAIN-ammo-cartridge-BELT-30-40/221993195778?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D45041%26meid%3Dbf29a179e7054bf58da85011a7e8bcd9%26pid%3D100005%26rk%3D6%26rkt%3D6%26sd%3D371482316578


http://www.ebay.com/itm/US-Buckle-BELT-Anson-New-Brass-WITH-ANTIQUED-STAINS-BELT-AMMO-CARTRIDGE-30-40/222441187342?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D45041%26meid%3Da5074a1e37f24fe5b5bd8dabe325f59f%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D371482316578

Also on EBay
I also saw a VINTAGE US ARMY BALLOON PILOT OBSERVER BRASS BELT BUCKLE PLATE on EBay sold for GBP 5.99
Approximately AU $9.84 with same M. Hartley Company Address marks

[Baltimore Ed]

Very nice find. I've got a 7th cavalry collar disc that I wear on my punitive expedition uniform. The 7th was also a part of Pershing's force. It's always interesting to me to see where the important players of WW 1 and 2 were before they became so pivotal. Pershing and Pattons exploits for example and how they create the man.