sirocco,
I've always heard that the Bastard Adams is tied with calf tail for the wing, and moose or elk hair for the tail.
So the pattern would be:
hook: dry fly 10-20
thread: 8/0 black (or grey)
wing: calf tail, divided
tail: moose hair
body: grey dubbing
hackle: one grizzly, one brown
The effectiveness of this fly derives from the visibility of the calf tail in comparison with the less visible grizzly hackle tip wings.
But you can substitute anything that is handy. I am partial to white macrame yarn in place of the calf tail.
Good luck,
Michael