Surprised nobody else has chimed in. If it's vintage (which it's looking that way to me from the pics) it's one heck of a marble. Meaning you'd literally see dozens of 2"+ handmades (which arent that common to begin with) before you'd come across an example like this.
If you've got a marble show or reputable collector in your area I'd encourage someone to take closer look "in hand", to evaluate.