I apologize for not getting back sooner. I am battling strep throat and enfluenza

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As far as "Koftgari for Dummies" there is nothing written. In fact, the only koftgari done at present is in India. If anyone finds a book, please let me know. Stuff in process....little tougher. If I bump into anything, I will post. Will get back with the niello question soon.