signed Coleman vintage hand thrown pottery bowl w/ green glaze, flower holder vase?

Signed Coleman pottery bowl, about 5" in diameter x 3 1/4" tall. Not sure of the exact vintage of this piece, looks maybe 70s or 80s to me?

Also, I have no idea who made this, aside from the Coleman signature. But I love the color, the unusual shape, and the rustic feel of this piece – it displays wonderfully even empty.