I remember being given a pewter beer mug awhile back, and tried to figure out what "pewter" really was. Seems that the recipie varies wildly. Some versions contain lead, so I ditched in in the trash.
Anyway, "pewter" is a wildly varying metal alloy. It may be mostly tin, it may have no tin in it. It may be up to 20 lead, or contain no lead at all. The no-lead versions usually contain copper. There are almost always a few other metals thrown in. All the metals are typically on the soft side.
Your milage may vary considerably