Ceramic pottery studio Ball Vase with appliqués

I would love to know who created this pot. I bought it in a second hand store in Toronto, Canada.
It is about six inches high and 6 inches wide. It weighs just over 2lbs.
It is what I call a ball vase because of its shape.
The layers of glaze are beautifully executed.
The appliqués appear to be possibly "shells".
They are letters marked on the bottom A D A. I am not sure if the marks under the ADA are marks or just marks from the creative process.
I would think it has some age due to the fact that the green felts on the bottom all are worn away.

Thanks