Years ago, after mapping out Eckankar trivia along a chronological timeline, I looked at the ten years after Paul Twitchell's death as highly significant. Most notably the relationship between Gail and Eckankar and how that changed!
Suppose for a moment that Gail's letters told a different story about Eckankar, about Sudar Singh and / or about Rebazar Tarzs, etc. Was that the case?
Before the book form of LTG I believe some of them were distributed to members in the form of a discourse, or something, which might suggest the letters were shared during the time of Darwin Gross.
Does anyone remember the "sale" between Gail and Darwin / Eckankar? and where Gail was released from all liability for the writings and given half a million dollars, etc?
Personally I see the years (1970s) leading up to the transfer of power (1981) and dismissal of Darwin Gross (1983) as pieces to a story connecting the dots to the truth vs. fiction of Eckankar history. In short, it looks clear beyond a doubt that certain things were changed and certain people knew about it!
I suggest the reason so many arguments persisted throughout the years about the Eckankar writings, history, dogma, etc. happened on account of what people knew and more or less refused to tell / share. Even dialogues continuing to this day with the spin and detraction away from certain subjects that might lead to the actual truth ... truths that others know, but want to control the dissemination of; wording it in their own particular ways.
Klemp & Marman have both written numerous paragraphs about topics of controversy that others have discussed and argued about for years. Harold Klemp and Doug Marman would have been in a position to know - given their time and experience with the organization - and access to Paul Twitchell's personal letters and manuscripts.
So what was known, but not necessarily told in plain language at first? (coming out slowly only over a course of many years? and amid online discourses between members, ex-members and the public?
I would submit there are potentially a number of particulars that perhaps some individuals well know, but still don't want to discuss, talk about or have enter the public domain. One problem I see is that truth is part of the spiritual teachings just as much, if not even more, than fiction, pseudo history and religion! And I think people will have that truth in spite of those who don't think it has anything to do with the "spiritual" teachings.