Al, I don't see a problem with Ron's post or McCullough's remarks..  That's really what happened.  What did not happen was scraping the furnace and making marbles from the scrapings.  That is the myth.  I bought some early in collecting and was told they were furnace scrapings.  It's in some books that they are.  That myth has caused the confusion.  It was a tall tale told by a glass worker.  Howard Powell has given me many "furnace marbles", but he knew what they were and were not.  This got discussed several years back, but I guess nobody ever wrote in a book what really happened.  Many people still believe the myth. 
The story about Wissmach is true Al, just like Ron said.