John, I have handled a couple of BSF (Barovier-Seguso-Ferro) pieces from the mid-1930s that look pretty crude, which only adds to their charm. I've also seen some later pieces, e.g. a vase made by Alberto Toso and some of those terrible modern animals, that were crudely made. So I can't say something is not Murano just because it appears crude. To me, all scavo looks crude -- it is supposed to look like it has been buried for a long time. Scavo goes beyond being frosted. It will look erose and usually have white patches on the glass that look like mineral salts. Certain techniques, e.g. scavo, pulegoso, and corroso are actually trying to achieve a crude look, so looking that way is not so bad.