I bought eight black asian chicks from TSC that are about 2 months old now. Most are solid black with the beautiful sheen, one has reddish brown mixed around the neck and several of them have white wing tips. The solid black ones look just like BSL but a few of them have white wing tips. Would they be Australorp with the white wing tips or do some asians have it too?
White tips are common with black plumage, I don't think you can pin down any specific heritage from them.