Old Blue Dun

from the recipe in The Founding Flies by Mike Valla

Hook: #12 - 14
Thread: primrose yellow
Tail: rusty dun rooster hackle barbs (three)
Rib: on strand of yellow buttonhole twist
Body: muskrat in a dubbing loop, first wraps should expose thread color
Wing: starling (optional)
Hackle: rusty dun hen

Head cement recipe:
Goop
Xylene (epoxy thinnner)

Instructions:
Fill a quart jar half full with Xylene
Squeeze a tube of Goop into the Xylene
Shake until the Goop is dissolved; add Xylene to desired consistency

Apply with a pin or needle dipped in the liquid

https://youtu.be/AJbvJUixaCs