Tim Hardin (wiki AMG MySpace fansite) was a rare major-label musician who served in Vietnam. The country of Vietnam, that is; actually, he left the Marines way back in 1961, long before US combat troops were deployed in the country.
In 1963 and '64, he recorded some demos for Columbia Records, which they declined to release. After all, bluesy folksingers were a dime a dozen in those days. In 1967, after Hardin had proven himself as a commercial songwriter and artist for another label, Columbia licensed the tracks out, though the tracks clearly didn't sound like Hardin's current output. (Hardin is, of course, best known as the guy who wrote "If I Were A Carpenter.")
This version of Stag is pretty clearly the template for the last two versions I've posted, including the surprise ending I like so much about last week's.