This reminds me of a D&D dice website that went into way too much detail about how they weren't fair and I remember photos of them stacked on top of each other to show the variations in manufacturing.
Zocchi retired, but his company charmingly continues.
https://www.gamescience.com/about-1
(Note: the sprue left by his sharp-edged process has since been proven to result in more bias than the tumbling undergone by the round-edged process.)