A cool find.

I found this 6 1/2 inch pie plate at the Salvation Army. I have been researching the markings on the back because there are one regular one; green castle with AA Bohn Germany. Then there is one imprinted which is in a circle and reads; . FRANZ ANT, MEHLEM. BONN RHIEN In between the Bonn and Rhien there is a tiny N printed higher up than the other letters and over this is a 1. Above the 1 is the M trade mark but the first hump of the M looks like a stick figure - head and all. Below the circle is AB with a sideways 4 under them. How old is this dish? Does anyone have any idea?
Thanks