Help indentify pottery marks

I have 3 pieces of viontage art pottery possibly from the 60's or 70's. There is a large mushroom shape frog vase and a small frog vase also mushroom shape. Also I have a small girl figure bud vase. All three are marked with a J= incised on the bottom. Has anyone seen this mark before and who is the potter?

Can you post some photos? Also, have you taken a look at our marks library at Marks & Library

Sorry my images are not responding when attempting to upload. I did try the library without any luck. Thanks