Sorry but I don't have any registers for the Third Cav. Maybe someone has something for you  

American uniform. He probably came home with those pins as souvenirs. I've seen a US soldier's stuff from WW1 and he had dozens of them. Whoever put together those pictures just threw in those pins.

picked these up at a garage sale last week, both are named and both have British cavalry cap badges. The uniforms look American to me but I’m no expert in so I’m not sure. Cool wall hangers regardless! 

This is a photo of a later commercial made German scabbard by Eichorn, it looks very similar to your example.  

It looks similar to the scabbard supplied with my Colt 62316 bayonet; the only markings on the scabbard are US M8 A1, nothing on the press studs or on bottom of guard. The hole in the bottom of scabbard is also smaller on my example and it has the crinkle finish. Yours may be from one of the German made scabbards.

That's suspicious in itself. You'd have to really know about that stuff to be able to say that and probably have some kind of provenance on it. And that paint job it too fine for me to be comfortable about it.   

yah, best case you get your money back. Definetly a messed up situation...

Nothing on the bottom of the guard. Just the USM8A1 mark and the marks on the glove fasteners.   For grins, here it is with a BMCO M8-marked M8A1.  

Nice set!  Can't help with any answers to your questions, though.  That's a new one on me. I appreciate the close up, detailed pictures.  Thanks for sharing it!

I am curator of Michigan's Military Heritage Museum and Michigan was where Custer called home and where his Wife lived out the rest of her years. We would be thrilled to exhibit these items.  We just received the sword of General Simeon Brown who rode with Custer as adjutant of the 6th Michigan Cavalry at Gettysburg and later commanded the 11th Michigan Cavalry.    Scott