Frank, Thanks for the information; you're right, that accounts for the steep price. I still like the hook, though.
Kelly, Good for you - that will work! If you're using a Partridge Bartleet CS10/1 hook in a #6, then the Spey and the Dee patterns are going to be challenging, since they're made to be tyed on much longer hooks. You can either try to get some 1/0 hooks, or you can try to use only the very tip portion of your hackles for hackling the body. I always struggle with getting hackles that are narrow enough to tie in on smaller hooks. But what you've got on the fly now will give you a great streaming effect in the water, which is one of the things that these Spey patterns are know for. Some people I know use lots of that old winging standby, saliva, to coax their mallard wings into position!
Duck flank feathers; from any type of duck, are definitely not my favorite material to work with!
Ard my have some pointers for all of us on how to work with and tie in mallard flank feathers.