Hello and welcome.
That is a Mexican Eagle mark. These were used from roughly 1948 to 1980.
Your newer style Eagle mark was used from about 1955 up to around 1980.
http://www.925-1000.com/mexican_marks.html" onclick="window.open(this.href);return false;
Looks like the number 104 which would be the manufacturer.
There was a "LV" that used the 104 Eagle mark, but I don't know who that was. (There could have been more than one firm that used that number.)
Information on Mexican silversmiths is hard to come by.
Pat.