Swirl ID-ing seems to be the most inexact of the present marble sciences. When people try to ID transparent swirls by maker it sometimes makes me laugh. Heck, maybe they're right in some of their more obscure guesses, but how can anyone be sure? To me there seems to be a lack of replicability to that part of the discipline. I want whoever I consult on that type of ID to be able to say "I don't know". If they don't have the security to say that with grace, then I will view them with some doubt.