I don't think I have seem such a long handle on a Burmese sword. Some funky Shan dha approach these proportions, but they have shorter blades, so the handle wouldn't be so long in absolute terms.
Its very possibly cross-pollination. You know how this stuff moves around! Nothing ever seems to be an absolute identifier.
Except I have convinced myself that koftgari on the blade is uniquely Burmese, at least on the older blades (I understand from Dan that someone up in northern Thailand seems to do it nowadays, since he sent his custom dha up there for decoration).
Thinking about the fuller. I haven't seen too many hatchet tipped dha myself. Not that they are especially rare -- I've just not had the opportunity. I have one, but it has no fuller. I had a concave-tipped one with a fuller that ran right through the "tip," though, very much like this one. I'm pretty sure that one was Burmese, but no idea from which tribe (the consensus is Kachin, though).