I always got them from Jonas at the Feathered hook. Braided golden stones. I never caught anything on them, but I always liked them as a point fly at big fishing creek. I always figured a big brown might grab that but not my standard walts worm, or PT soft hackle.
I have some in my steelhead box, but I mainly use my fur stonefly pattern with a crystal braid hot spot for steelies... where you want as much "bugginess" as possible. Thats the one drawback about braided flies, but they usually have a good silhouette for dirty water and are worth having imo.
Not sure about erie, but stoneflies are important in NY.