19th century Mexican silver dish...I think! Help!

[lhaschke]

Am trying to correctly identify this Mexican silver dish I inherited. It appears to have three of the four marks on the .925-1000 website's photo of 19th century Mexico marks. Here are the photos:

https://picasaweb.google.com/lhaschke/MexicanSilverDish" onclick="window.open(this.href);return false;

If anyone can provide information on what these marks mean and/or ideas to purity, I would appreciate it.

Many thanks!