Alan,
It is well known to be something of a takeoff of on the Tups Indispensable. Are you not familiar with Bob Carmichael and his patterns?
Bob Carmichael didnt use the fur from a ram's testicles.
Sorry, I didn't quite do justice to Bob Carmichael's pattern as the abdomen is not silk, but a dubbing material.
Below is AlanSheperd's version of a Tups Indispensable from FAOL's Old Flies section.