Not sure here if we are talking about bowls or balls!
Lignum Vitae was once in high demand for bearings in very large machines - like the shaft bearings on ocean going ships. My dad was on a destroyer in WWII that had lignum vitae bearings. I used to manage several very small hydroelectric plants that dated from about 1910 and they had lignum vitae bearings as well. It will not rot, holds oil well, and absorbs vibration much better than anything else. When we tried replacing the old wood bearings with their synthetic clones, the machines developed uncontrolled vibrations and we had to go back to wood. Super expensive even back in the 1980's.
It is reported to make great mallet heads and impact blocks for driving items into place and was once a staple in a mill wrights tool box. Not sure you can finish it as it is so dense nothing will likely penetrate the surface.
Have fun, a rare find.