Quick note, found a litte more info:
Chris said here, Iding Acme Realers From Pictures, that Gino Biffany "originally - and mistakenly - believed that Acme Realers were opalescent baseballs. he later found out that they are actually opalescent peerless patches."
Does that explain why so many people, including Block and Marble Alan, thought realers were rainbos? And what about that partial box of rainbos? I think it would be interesting to know why Biffany first believed they were rainbos. Is there any chance it is because rainbos were also sold under the realer name?
Well, I don't expect an answer about the possible cross-over nature of the realers, not right away. I'm ready to put it on the back burner.
About any other rainbo types ... Dave, did you happen to find anything out about any other rainbo marketing names? (I know you're busy. No rush. Just asking while I'm thinking about it. :-)