Hello Harry,
Unfortunately, I am afraid the new photos don't help too much.
Generally ivory, nicely polished horn, bone and not to mention synthetic resin are very difficult to distinguish from photos.
Ivory has a specific structure and can display concentric circles (similar to the ones in the section of a tree). But the scales are rather small and you might have absolutely no structure at all.
I agree with David regarding the tests proposed. First test mentioned above does not work and the second one might be damaging EVEN FOR GENUINE IVORY!
For your very nice Choora, my best guess is ivory or bone (but more likely bone). I do not believe the two round inclusions to be enamel, but most likely the same material like the scales. Both bone and ivory can be easily polished to be perfectly flush with the pommel.
However, in my opinion it doesn't matter too much whether is ivory or bone. It's a nice knife anyhow!
