I don't know how many here knew about it, though I suspect that "ancient, arcane sources" might be a bit of a stretch, since Villard is one of the better-known biographies and, like Hinton, is still in print. The Hoyt/LeBarnes proposed breakout was mentioned in Renehans's "Secret Six," McGlone's "John Brown's War Against Slavery," both in the last 2 decades and also in print. It's also in McMaster's general "History of the People of the United States," which, while not from the last 75 years, was a widely-read general history that went through eight editions - the reason I mention it is that it was a "Yankee" history and got McMaster the chair of History at the University of Pennsylvania. All that said, since the conspiracy did not actually get anywhere, I am not surprised that it is not mentioned more.
But that it has not been "hidden away" was not my point. My point was that where you have (as I read it) posited one huge conspiracy to break Brown out that included those from Kansas and the Secret Six, there was simply not as far as I can tell. Though I would be happy to take a look at whatever evidence you might want to throw out in that direction. I should especially be interested in any contacts between later members of the Kansas Seventh (Jennison, Brown Jr, Hoyt, Anthony) and members of the secret six before Brown's trial ended.
"I'd just like to see a little clarification as to your inference that this information is so well know that it was innocuous in my book..."
My inference is not that it's well-known, but that the statement "it's never been in print before" is false. It has been in print continuously for at least a century.