[Ian]

ausjulius, werecow, krockew,

Thanks for your suggestions. Yes, the truong dao from Vietnam is another version of the dadao, hence its similarity to the original post (OP). However, the firm provenance for the one I show -- a Belgian officer's bring back after serving in the Korean War (1950-1953) -- makes a Vietnamese sword very unlikely. The sword was collected in Korea more than a decade before the Vietnam War. The OP is either Chinese or Korean IMHO.

After looking more into the history of the Chinese dadao, I'm inclined to think that the OP was introduced into Korea via the Chinese People's Volunteer Army (PVA). There is some evidence to indicate that the dadao remained (unofficially) in some units of the PVA up to about 1950 as a cherished weapon celebrating the resistance to the invading Japanese. The dadao was a close-quarter's weapon in the fighting against Japanese forces in the 1930s and 1940s.

So far I have not found any evidence of the Koreans (either North or South) using the dadao in their military ranks.