Thank you for giving me the information and where you got it from.  I wasn't doubting you at all but even after you've given me the information and where you got it from I'm still not finding what you're finding.  I'd be interested to know if anyone else on this forum can find what Laurent is seeing?  On Ancestry.com I'm not finding an Albert C. Hauck born in 1913 and who died in 1993 no matter where they were born.  I looked in the Internet Archive at more than one of the The Register of Commissioned and Warrant Officers publications and did a search for just Hauck but could only find one August C. Hauck who was born in 1906, so I don't know.  I must be having an off day or something.      

These are steelbacks with the same backmark.   

Thank you for the comment. I would love to buy a copy of USMC Eagle, Globe, and Anchor Emblem Pictorial Guide", but they are pretty expensive. I'm hoping I'll be able to get a deal on a copy in the future.

A new addition, an experimental 1906 Rock Island Arsenal .38 holster, in Scott Meadows' holster books he writes that 180 were produced and that they were tested by the 13th cavalry, he also shows are a couple of great period photos of the holsters. Originally but now missing there would have been a leather tab at the bottom with  a tie down thong. It ticks two boxes for myself being a keen cavalry accoutrement collector along with a preference to 13th cavalry related items.

You have a model 1840 heavy cavalry saber which looks to be in nice shape. It is likely a European import.  Is there a marker mark on the blade or letters on the pommel cap (end)? A picture of the scabbard l would help  verify country of origin. 

I can't quite make out this maker mark and can't find it anywhere outside of a few I found and these pics from one ebay listing. Could be Jaffe & Jaffee or Jaffes Jaffe.   Nothing in Directory of American Military Goods Dealers & Makers.  

Nice collection of ega’s. I am going to step aside and let a few others who are very knowlegable here answer the question on exact patterns. My references are still in storage and I have been a bit rusty lately, but I think it is safe to say that the majority of those are WWII and earlier, and a few pretty deferrable ones. Good luck. 

Blade has some light finger print rust marks I may get off but that’s all I’m doing if it is an original 

HCU-1 Senior Chief Diver in greens at Eniwetok (and adidas sneakers)  

Aye, Japanese made