Doubt if there's a problem with attribution as I believe Walt told me pretty much the same, but I could be wrong. At any rate, either you're correct and I'm correct about what he said she said, or we're not. I suspect the weight savings aspect itself is correct because there is a seller on an auction site bragging about his conventionally-ribbed Flues 4e 16 gauge weighing a "light" 7lb. The 12 I have with the swamped rib weighs the same.

jack