1940's Mexican Pottery Charger

Any idea in what region of Mexico was this one made? I guess the 1940 date on the back was put by the previous owner and the piece was made around that time? The rest looks like Beth from Iran? MCS? Or maybe the writings are by the decorator?
Can't tell for sure but the round impressed mark likely reads Made In Mexico. The molded black medallion in the center is not very clear but looks like Maya calendar or so.
Thanks

 

Is that an Aztec calendar in the middle? I can't see clearly enough.

 

I think it is. The mold is not very crisp.

 

I can't get the first two pics to enlarge.

Is the peachy-orange ring actually 3-dimesional or is it an optical illusion because of the way it's painted/shaded?

I think it has some similarities to Ladislao Ortega pottery and the round impressed maker's mark looks like it could be his.

Otherwise, look at Mexican opaque pottery for some ideas.

 

Only the black center is 3d. The rest is flat, painted over.

 

Is the decoration the powdery cold painted "opaque" technique, or is it burnished, or glazed and fired, or some combination of those techniques?

 

A gift from "Gran" somebody to Beth. Her grandmother?

 

I don't see 1940s. Are you sure date doesn't read 1990?

Debora

 

To me it looks like 1940. Will post close-ups soon.
The paint is over the bisque or the applied slip. I think that it was not fired.

 

Here's a similar plato (which certainly could be from the 1940s.) Credited to the state of Querétaro, if that helps.

Debora