South Korean Special Forces used this camouflage pattern in the 1960’s through 1980’s (source: https://camopedia.org/index.php?title=South_Korea, https://iacmc.forumotion.com/t5541-unusual-us-special-forces-advisors-uniform-south-korean-wave-noodle-pattern). It was also exported to other countries as well (source: https://iacmc.forumotion.com/t11731-my-rok-stuff), most notably Iraq, Ethiopia, El Salvador, Peru, and Guatamala (source: http://vonstuckcamouflage.free.fr/south-corea.php).
This jacket was exported to Ethiopia for the DERG regime, which provided training for ZIPRA starting in 1977 towards the end of the Bush War (source: https://www.wilsoncenter.org/publication/robert-mugabe-and-todor-zhivkov), before making its way south to Rhodesia where it was used by a ZIPRA insurgent. The item was recovered at the Guineafowl School assembly point in Gwelo (now Gweru, information provided by seller), along with the Strichtarn and Egyptian shirts. Like many insurgent-used items, it shows signs of heavy use. The fabric is relatively lightweight, meaning it would wear very quickly in field conditions.
Red collar board remnants at stitch lines. An example with intact collar insignia can be seen here: https://www.newrhodesian.ca/viewtopic.php?p=50832&sid=d2a06be7a13f17c4415b4c9ba1edc348#p50832
Buttons fell off.
Flight jacket style zipper pocket. Zipper has rusted shut.
This one is less faded, has an intact tag, and a functioning arm pocket zipper.
Red thread for collar tab.