I picked this one out of "Flies of Scotland". I did tinker slightly with it by giving it a tail of mixed 50/50 Globrite flosses nos 11 & 12 instead of the original No12 only.
Thread - No 11 Globrite floss.
Tail - 50/50 Globrite flosses nos 11 & 12
Body - Two layers of 11 Globrite floss
Overbody - Touching turns of pearl lurex (I dab a bit of varnish on the underbody first)
Body hackle - Black Cock.
Rib - Ex-fine oval silver tinsel or silver wire.
Head hackle - Black hen
Head - No 11 Globrite floss