Well, my first stray thought is that Akro ads would compare their marbles to styles that their target audience's fathers would have played with.
On the other hand that could have just been an adwriter's fantasy.
On the third hand, have MFC and Akro (and anyone who called their glass "onyx") trying to get into the older-fashioned stone market.
Soooooo .... it's feasible that the Master owners would have been in that frame of mind as they tried to think of their own signature style.
But that's all I got. "Feasible".