Nice piece. That is a "Shan" dha hmyaung. The people called the Shan by the Burmese call themselves Tai Yuan (northern Tai), and live in an area across eastern Burma, southern Yunnan province (China), northern Thailand, and Laos. These guys are worn more at the western end of the territory.
It should have a cord wrapped around the scabbard near the throat, with a loop - a mini version of the cord baldric on a dha-shay (sword length). The cord is looped over the waist sash at the left side, with the dagger hanging down, as shown in the photo below.
I tend to think that the round cross-sectioned scabbards denote an origin more to the north, in Yunnan, but I have no particular basis for that other than the fact that one of the two that I own was collected in Yunnan:
