Hook - Mustad 3906/3906B
Thread - Black.
Tail - Small bunch of black cock hackle equaling the hook length.
Back - A strip of black crow wing or substitute, doubled over lengthways and reaching almost halfway down the sides of the fly, tied in by the tip end.
Body - The original dressing has an underbody of black marabou silk, wrapped with a strip of clear plastic from a particular washing up pot cleaner. Clear Vinyl Rib or Nymph Rib can be substituted. They are three times thicker, so the underbody can be eliminated.
Hackle - Two turns of black cock, the fibers the same length as shank (leave full, not gathered underneath into a throat style).
Reference - Fly Anglers Online (FAOL) Archive