Getting back to your original question, I think there are times when a large Royal Coachman will take bass fairly well. Watching bass, even small bass, explode onto a dry fly is a lot of fun. I would replace the feather wing with either white calf tail, white bucktail, or white deer body hair. I think the latter will aid floatability the best. I would also replace the red floss with holographic red tinsel. The tail might be best if it were also hair. At this point, it may have been modified to the point that it isn't really a Royal Coachman, but it would certainly be more durable. When I tied them with white quill wings, my Royal Coachmen would be badly mangled after only a fish or three. Hair is much more resilient.

Good luck,