I had to get Elton to ID this one for me, he says it's a Pittsburg U-240 that the, "glaze did not fit, it shrunk more than the porcelain when it cooled." I've pictured two views of the same piece to show the crackled glaze all over it, and the other a straight on profile.

Thank you Elton for your continued dedication to the hobby in helping us identify our finds.