Then using this pattern:
pattern2.png

I ran thatch again, setting the result to 30% multiply as well:
mtn_hf3.png

And a third time with this pattern:
pattern3.png

With one last run of thatch, with the result to 30% multiply:
mtn_hf4.png

I think by tweaking the patterns, possibly making them more turbulent or noisier, I could even get closer.

-Rob A>