I believe everyone here would generally agree that this is military related and tied to Quantico in some way. But once you get into the multi-connections through theory and leaps to reach Raider you lose folks. Reducing things to the simplest meaning here is the likely way to attribute as I doubt someone was leaving that many easter eggs.    Probably a Marine stationed at Quantico in the 60's that wanted a cool motorcycle helmet. 

Great find! I like the shield design. Ten bucks all day long!

Nice !

Looks like the pattern 1903. Not completely sure that's the correct designation, but it's the type that preceded the 1910 model.

Well, this complicates my hypothesis a little bit.  This uniform has cropped up. It's nearly the same, except it has an "E" instead of a "T"

Ohhhh, I thought that was in country service which I thought was a bit long… thanks for the clarification.

The badge you show is an officer's badge.       From  -  "IDENTIFICATION BADGES/AWARDS/INSIGNIA 5201 - Breast Insignia"    u. Surface Warfare Insignia Description    (1) Surface Warfare Officer (SWO).  A gold metal or embroidered fabric insignia with the bow and superstructure of a modern naval warship on two crossed swords, on a background of ocean swells.      (2) Enlisted Surface Warfare Specialist (ESWS).  A silver metal or embroidered fabric insignia showing the bow and super­structure of a modern naval warship on two crossed cutlasses, on a background of ocean swells.     The complete article can be found here -         https://www.mynavyhr.navy.mil/References/US-Navy-Uniforms/Uniform-Regulations/Chapter-5/5201-Breast-Insignia/#Surface Warfare Officer (SWO)     Larry  

Two young men on the boat. Looks like they are on their way to war. What is the belt they are wearing?     

STOP! you are reading into that 67-70. His total time served was 3 years. You have no idea how long he was in Vietnam so do not say things you can not prove! Most guys did one tour of Vietnam. One tour equals one year. That is all you can say with any degree of confidence.

I agree that year apostrophe's should precede the two digit year but also remember.... Marines. Juuuuust saying.