One of the $25 has the ring and 2 don't of the 3 different $25's I have. the white inlay does have the ring.

One is a later hub mold. The hubs are rectangles on your brown scan and not true retangles on the green scan. The end nearest the center is narrower. If I remember right the non rectange is the later mold.
Mason also made 1 1/2 inch and 1 9/16 inch chips.