1903 for MFC.
Martin Christensen's 1899 sphere making design was revolutionary. He used it first with ball bearings and made a fortune off that. Then he moved to marbles. He got Leighton to teach him about working with glass.
1914 for Akro.
Before 1914, Akro was a jobberer. They bought MFC marbles and packaged them up pretty for sale.
Then the embezzler Horace Hill stole MFC's glass formulas, machine designs and client list. He left MFC for Akro. He tweaked the machine designs enough to get a patent for a "new" design so that Akro could legally start production. And that is how Akro got into the marble-making business.