You can see Bob's tie of his creation and his original recipe for the Cutty on pages 100 and 101 in the incredible Fishing Atlantic Salmon; The Flies and the Patterns, authored by Joseph D. Bates, Jr. and Pamela Bates Richards and edited by Bob Warren (Stackpole Books, 1996).
The pattern for the Cutty as I've come to tie it:
Thread: gordon griffiths 14/0 Claret
Tag: fine copper wire or oval tinsel - sized to suit fly size
Tip: either the floss blend (see below) or your orange floss of choice.
Tail: same floss as tip
Butt: black beaver dubbing
Rib: fine copper wire or oval tinsel - sized to suit fly size
Body: rear half flourescent green floss, front half peacock herl
Hackle (throat): black hen
Underwing: floss blend or peachy orange floss to tag under green flourescent floss to tip of tail
Wing: tented teal
Bob's original recipe calls for a blended floss in the tip and tail. I had never blended floss (nor even thought of blending floss!) until I met Bob and the Cutty Sark on the Miramichi in the late 1990's. When I was first figuring out how to tie the fly, I relied heavily on Renate Bullock (http://www.bullockslodge.com/) for help. She told me about Gordon Griffith's floss, and about the blend Bob uses on the fly. Using all Gordon Griffith's floss, the blend is 4 parts orange, 2 parts yellow, and 1 part green. Fortunately, Griffith's floss divides easily into 2 strands; if it didn't, you'd end up with a clothesline if you blended "full strength" lengths of floss. I do use it in the underwing, topped by a strand of green floss.
The ingredients and the blended floss:
The blend tied in (view of underside of fly):
I have a favorite orange floss for butts or tips on atlantic salmon flies - it's an old and discontinued (as far as I can tell) Danville floss. It comes on a wooden spool and is labeled Danville Depth Ray Nylon Flourescent. I use it on the Cutty Sark rather than the pale orange floss that Keith lists for the pattern in his book referenced above. And it seems to work. This 18 pound hen was swimming innocently enough in the Northwest Miramichi when my number six Cutty Sark swam by and grabbed her attention. My guide looks a little goofy but he was a nice fellow donating his time to the Miramichi Salmon Association's Classic, a delightful couple days of fishing that benefits that organization. It is NOT a competition. (photo by Wally Murray):
Bob's experience with the Cutty Sark indicates that it is most successful as a size 6 fly. I'm a believer!