Hi Colin! Here are some crossbows from the Branly Museum that look a lot like one of yours.
https://www.quaibranly.fr/fr/explore...alete/page/10/
https://www.quaibranly.fr/fr/explore...bambou/page/6/
https://www.quaibranly.fr/fr/explore...nnerie/page/6/
They come from Vietnam, from the Central Highlands (otherwise - the Central Plateau). There are the provinces of Kon Tum, Gia Lai, Dak Lak inhabited by mountain peoples such as Sedang, Bahnar, Gia Rai, Ede and others. During the Vietnam War, the legendary Ho Chi Minh Trail passed through these mountains, and heavy battles of American soldiers and their mountaineers supporting them against Vietnamese soldiers and communist guerrillas took place. Participants of those events brought not a small part of the crossbows to commemorate the war.
Items from the museum date back to an earlier period - the 1930s, most of which belonged to the Sedang people.
Color photo - 1974