TRIGGERNOSISI got it here @ Arizona Arms --- good guys to deal with.
http://www.davidsonsinc.com/consumers/subsites/dealer_home.asp?dealer_id=479138This was a Distributor exclusive (TALO) so I'm not sure about current availability, but at the time this outfit had some at a fair price.
I should add that I bought the Elk antler grips from a grip maker. The Flattop came with black, plastic grips which also worked fine.