Just a quick tying suggestion guys - layer the wing. (and use the softest goat hair you can find).
I suggest building up the hair wing in small bunches. Each bunch slightly longer than the last. You will create a lovely taper to the fly and its swimming properties will be so good you will see why salmon are so attracted. Promise!
Here are some being shown to me by a local expert angler on Norway's river Reisa. A big salmon river!
The longest I saw was 9in long!