Tin is an element (Sn) that shares the same line (IV) on the periodic table with lead. It is a completely different metal, and has been used for years for canning foods (tin can?) in many alloys of copper, nickel, zinc(including solder) and as you know in decorative uses.
Can't guarentee that lead would not be present in antique tin as an impurity, especially if soldered, but tin is tin, not lead. Would be easy to test using one of those test swabs.