Interesting choice of sample text. I used to have a script that looked a lot like that, but it was heavily featural rather than derived from a natscript.
Unfortunately, even though I wrote the titles of several documents in it, I can't find the actual key for the damn thing.
...although now that I think about it, maybe this other (non-featural) alphabet would be closer:
I had a few scripts that were more similar than those, but I didn't write much (if anything) in them.