Had the luck of seeing this the other day. Was talking with one of my teachers when he mentioned that his father was a Vietnam Vet and mailed several items home, including his helmet cover.
The helmet cover belonged to SPC August "Gus" Stackhouse of New Jersey. He was in the Army from 1964 to 1968. After serving a stint in Germany, he was sent to Vietnam. After working initially as a mechanic, he was attached to an infantry unit of the 173rd AB and earned the Bronze Star.
The cover itself is made of twill fabric. With a production date of late 1964, early 1965, this fits within the time frame of his service. Most of the graffiti was done in one sitting towards the end of his tour, but there are numerous parts that have faded and were re-inked several times (this is more evident in hand). The band is also graffitied heavily, with a count down and several phrases on both sides.
This was pulled from the original packaging (envelope which also contained a SPC patch and several medals) which the cover was mailed home in. I did not take a photo of the envelope though
Overall, it's a really cool piece which has solid provenance behind it.
I hope you all enjoy it as much as I did