They were very competitive, these two companies.
There are many stories of some very dark stuff that may have occurred between the two. Ultimately Master Marble Company won out and purchased Akro. The Japanese influx of marbles eventually shut them both down.
Master Glass Company (the newer name for Master) used Akro boxes and marbles in the final sales era. They never did too well aesthetically with their cats-eye rendition but they tried and of course they worked.
I love a good Master Glass Catāmost are pretty crappy looking but some are just killer.
Hope this helps,
MarbleāOn!!