These are rare, but not to the level of only a handful exist right? I own one and I've seen 2 or 3 for sale at various places just in the past year. 

Welcome to the Forum!   It is hard to judge the originality of the painted insignia from the photos, but they are not US.  Maybe British...they had a complicated system of unit markings.     The helmet shell being US made is not surprising.  I am trusting your identification of the stamped markings, but steel helmets were something that were made for the British in American factories before the US entered the war in 1917.  

The ANG had four F-100 units sent to Vietnam and two to Korea in 1968 due to the Pueblo Crisis. An in-country active duty unit, the 355 TFS, was mostly manned by ANG pilots. Your patch above was when the KANG had the F-105 training role in the 1970s.   Randy

I believe my family and I returned to CONUS aboard the USNS Geiger in August '63, Bremerhaven to NYC. Can anybody confirm 'this route and date? 

I knew it happened in February 1945, but not the details as described in the newspaper article 🙂   Unfortunately it doesn't report on mr Rayner's insurance claim adjuster's reaction 😂    

The  differerent paterns of the grenade vest Hand grenades and VB rifle grenades

I have done some research on this vet - Bedford Samuel Fox, and he was reported as part of the Medical Detachment at Walter Reed Hospital. Listed on the morning report of that Medical Detachment dated Feb 28, 1922, Pvt Fox was transferred to the Detachment Patients on the 27th of the month.  Its a bit puzzling and I am not quite sure if that means he was being treated at Walter Reed and then was finally discharged or whether he was part of the Medical Detachment (i.e., had transferred from the Infantry to the Medical Corps) after the war? 

Hello, I would like to ask if anyone could help me identify this helmet. Is it original? I think so, you can even see the rest of the ZC7 marking which points to Edward. G. Budd Manufacturing Co. I would need help identifying the division.  

I was going through my copy of Lazlo's book on the WWI Interallied Victory Medal and found this reference to the same sort of document that I have in this grouping (page 35):