Liquid Measure from Mexico?

Can anyone tell me the maker of this piece? I believe it is a liquor measure but if this is not correct, please let me know. From what I can make out on the bottom, the stamp is of 3 owls on a line with the middle owl being slightly larger than the other 2. I can’t make out the name of the company. Looks like it begins with the letter “S” and ends with “as” or “ar”
Under the company name is Mexico and below that is Sterling. There are also two additional markings - the Letter A and a symbol that I cannot make out (a shield with the number 1??).

Any suggestions? Date of origin?

Thanks!
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Shot 1.JPG