just to add a little more confusion, the other marbles found with these were the burnt sparklers. ;-)
check page 79 of 'mfc, and the perfect glass ball machine'. I am betting that most of what akro bought were the bricks. just a hunch, since i was not there either. also in that book is reference as to the colors MFC used.
They also did experiementation, (but according to the book, these were usually done by factory workers and taken home).. but I doubt akro would have dumped them. they would of either sold them or used the glass?
and to get back to the topic, we also have this style popeye, and auger types etc. sorry for threat jacking... (shame on us Galen.)