these are pseudo-hallmarks, imitations of silver hallmarks found on non-silver articles as well as foreign goods being passed off as something else. pseudo hallmarks are usually found on early chinese export silver, late 19th and 20th century wares from hanau germany made in an 18th century style, some american coin silver, as well as old pewter.
your marks are probably scottish pewter pseudo hallmarks from the 18th century. the top mark is a rose and the second mark is a thistle, these two pseudo-hallmarks were used on scottish pewter in the 17th & 18th centuries. the third mark appears to be a 2, which may somehow refer to the quality of the alloy. it appears that the maker's mark is worn.
now how this centuries old scottish pewter spoon ended up on a mexican beach...