Edwards' recipe calls for coch-y-bondhu hen hackle (black center with red tips), while previous recipes I have seen for "Greenwell" variations generally called for "furnace hen hackle" or, more recently, "Greenwell hen hackle". Remembering a nice little coch-y-bondhu hen skin that I've had for a while, I have attempted to come up with an acceptable version:
Hook: Daiichi 1530, Size #16
Thread: Pearsall's Gossamer #3 primrose, very heavily waxed (sub for Gossamer #4 light yellow which I do not have)
Hackle: Coch-y-bondhu hen
Rib: Fine gold wire
Body: Thread wraps