Black SPH-4B - Seems like a cool find

[YesMan-1]

My brother found and gave me this helmet as a Christmas gift and since then I've been trying to learn all I can about it. According to the Ebay seller, it was used by her father, this gentleman, during his career in the Army.  I cannot for the life of me find another non-replica black SPH-4b for sale anywhere, so it seems like it's a pretty cool find. If anyone has more info on these I'd love to know more!