Totally agree on the blank cards Talesof....just don't see how this one would outfit that. Have seen many over the years.... But, I can always learn something new!
Now as to the hallmark....
Since there is not directorship letter, this had to be made after 1965. However, if I am seeing this correctly, Tiffany&CO as i see it on your piece isn't how Tiffany did their hallmark. They used a superscript underlined o such as Co . (Sorry best way I could do it with the tools above.) Can you make a better picture of the hallmark? Thanks!