Dan is, of course, correct that the dha (daab) is Thai. It is difficult to see much from the photos, but it does appear to have some age to it, which I find very interesting, because the blade shape, handle binding and scabbard construction are elements commonly seen on contemporary Thai daab.
I've got a few older Thai swords with similar features, and it appears this is, perhaps, an "archetypal" model for modern daab.
It's hard to give an accurate estimate of age from photos, particularly since I've grown accustomed to using visual construction and styling cues to help do so. The ubiquitous "early 20th century" is my guess.
Cool sword.
P.S. Dan, what did you mean by "old" scabbard construction techniques? I see what looks like metal bands around wood, which is something that appears frequently on modern daab. What am I missing here?