For your consideration I have a rare gem Green Ebonite Nitro/R. Great condition for its age with normal signs of use. Ball has engraving above fingers. Span is 3.5" on the middle and 3.75" on the ring.

Brand: Ebonite
Ball Type: Ten-Pin Bowling Ball
Color: Green
Coverstock: Reactive Resin
Features: Drilled
Country/Region of Manufacture: United States
Sport/Activity: Bowling
Finish: Polished
Item Weight: 15 lb
Vintage: Yes