This wonderful map of Indochina was made by someone named Lucien Boucher of Paris during French colonial times. Unfortunately, I cannot find a date. I found this old map, along with many other fascinating images, on a website about the French “barefoot explorer” Auguste Pavie (1847-1925), https://pavie.culture.fr/home.php, who roamed around Laos, Cambodia and Thailand in the late 1800s.
nice