I certainly do not disagree with the statement that Riedel made some great glass. I simply feel that almost every house that produced glass in the period produced green iridescent pieces, a large percentage of which can not be identified. The list of companies that made iridescent green glass is quite long, and contains both well known and obscure makers. My point was, that unless this particular shape can be linked directly to Riedel, a Riedel attribution would be extremely difficult to support.
Craig