Another gem Adrian..... and we certainly enjoyed your "foray"!
I think reading somewhere that Glasso often used hooded merganser flank feathers in place of the Bronze Mallard in some of his variations of the Gold Heron and Brown Heron flies...and again at the collar....
Russ's posts were so incredibly helpful....It's always a bit fun researching Glasso's flies online. He tied variants of his patterns, substituted materials from time to time, and also tied variants at the request of friends.
I enjoyed reading Russ's (@flytyer) take on Glasso's flies here on Speypages (such a wealth of info - worth a tyer's time to search for @flytyer's posts).
I think reading somewhere that Glasso often used hooded merganser flank feathers in place of the Bronze Mallard in some of his variations of the Gold Heron and Brown Heron flies...and again at the collar....