Yet I came across these dead wet mint beauties at a flea market. Guess there are a few good ones still out there. 5/8"-25/32" The black and orange is actually is a deep transparent red
Made to profit off Akros good name. I believe they are Vintage
http://cgi.ebay.com/1960s-ATRO-AGATES-5-STAR-60-MARBLES-ORIGINAL-SEALED-/310296690576#ht_1958wt_1089
More than likely it was the glob of glass left on the punty from the previous marble that creates the inner core. No need to clean the punty and also save some glass.
Usually the end of cane would be a drop shape or occasionally pushed onto another cane while molten sometimes resulting in a marble with 2 completely different halves.
I believe Greg was saying he did not believe you would bother to comment. Not expecting you to. And even though we go over the issue every couple of years maybe someday someone will spill the beans one way or the other.