In the 1979 film Apocalypse Now, the character Captain Willard (played by Martin Sheen) portrays such a US soldier in Vietnam while famously wearing a 6105-8110.

Brand: Seiko
Reference: 6105-8119
Year: 1976
Case: 44mm
Strap: Black waffle rubber strap
Box/papers: No
Location: Los Angeles
Price: $2,499 or make me an offer :)
Web/IG: keepiece.co

Pictures: https://imgur.com/a/ez0ZUPv
Timestamp: https://imgur.com/a/JGgx7X2

CONDITION & SERVICING
-Case is unpolished and overall really nice example.
-Hands have darken more than indices.
-Service history is unknown.