I will be curious to hear what they tell you, Mike. I contacted them a couple of months ago and they told me the blue one was slightly different but they stopped short of telling me what the differences were. Since then I bought one out of curiosity. They did say they had discontinued the copper sandwich gasket from lack of demand. As I said the blue one is better than the one they had in the mid 70s. About the only thing I remember good about it was all the water holes were ringed in metal. The gasket itself was nothing to crow about.
