Help with mark on brooch

[rainbowtree117]

Brooch is marked 925 & 1MB. There is a mark below that I don't know? Any information on age, origin, maker would be very helpful.

[evelyb30]

It's Mexican, and has the Taxco eagle, telling us it was made prior to 1978.  Beyond that you've got me.  That's a "two blokes in a shed" piece as a British acquaintence would put it.   We don't know the makers on most of these. 

[rainbowtree117]

Thank you very much! Happy Thanksgiving!