It looks like an Americanised Tup's Indispensable. Similar body colour scheme but with tail and wings added. The hackle was originally, if memory serves, Honey Dun. The fame of the Tup's came from the material used in its dubbing, which was, for many years, a closely guarded secret. Somewhere I may still have one tied to the original dressing by Dr Malcolm Greenhalgh.

If you want to know more take a look in the "Just Old Flies and Stuff" section for an article by Alan Shepherd, called Tup's Indispensable. Though the fly shown there falls into the usual trap of modern imitations. The yellow silk section of the body is far too large.

The similarity in colours and name would lead me to believe that the Tup's is at least the inspiration for this pattern.

Should you tie the original (and we demand you do) we require photographs of the entire process. A tip, Unless the tup is securely restrained do not use tweezers to gather the dubbing!

Cheers,
A.