Very nice dhas!
And you're correct, the shorter one is Burmese and the other one, which I like very much, is a so-called Montagnard dha.
When you want to part with it, please let me know!
And yes, the handle material by the Burmese one seems to be ivory and by the Montagnard the grip seems to be made from bamboo.
Regards,
Detlef