Alan,
Rather than a Clyde style pattern, this sounds more like a Glanrhos design.
Here is a sample in that style:
And here is a link to the video where I tie up the pattern - as always, please view in HD, if able:
http://www.youtube.com/watch?v=KxOO6bACJV4
A much underutilized design and patterns, btw, these Glanrhos flies. They work well as a standard winged wet, but also fished 'dry' in the film.
Cheers,
Hans W