I am originally from Missouri (live on Kauai now). The Crackleback originated with Feathercraft in StLouis.
I have been experimenting with a variation of it. I am real fond of the marrying of brown and grizzly hackle like on the famous Adams
Please check these out on my little blogsite:
and let me know what you think
I have done well with the Crackleback when nothing else would move fish