California studio pottery ID?  

Wondering if anybody can ID the maker or studio that produced this vase? The story I was told when I bought this piece is that the shop owner purchased it from a little old lady who bought it from a gallery in St. Helena, CA (Napa Valley) in the late '60's for $250. The pot measures appx. 19" across at it's widest point, and about 9" tall. The hole in the top is around 3" in diameter. There are no discernable marks on it, inside or out, nor on the bottom. The inside is striated just like the outside. It's big and heavy, yet balances perfectly on it's narrow base. Thanks for any help anyone can give!
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