The kukris I have shown so far are all from 4 sources: The Victoria & Albert Museum, The Wallace Collection, The Gurkha Museum and The National Army Museum. That is one of the reasons I ask that no one uses these pictures for any reason. I could only shoot these pictures after signing agreements not to use these except for my own use. I wish I had better images to show, but I didn't have a digital camera.
The consensus about the crosshatching is because the watered blade had some defects. No one at the Wallace Collection had noticed it was watered and was a wonderful surprise for them. What an amazing collection. If any of you go to London, do not miss going to see the arms & armour.
N2, I would have to say the models are a steady progression from different regions rather than cultures, jats or ethnicity. Practicality certainly plays a large role and kukris have evolved to what we see today, good or bad. The older models certainly reflect a level of craftsmanship that is just not possible today unless one wanted to spend thousands instead of hundreds on a new knife.