I don't think William Grady considers himself a part of any movement, and certainly his book wasn't about the movement.
Dr. Grady has made msny You Tube videos advocating the KJVO myth, as well as writing several boox advocating that myth. If he's not part of the movement, then neither is Gail Riplinger. Thing is, he repeats some of the claptrap from Dr. Wilkinson's book, which is the "foundation stone" of the current KJVO myth.
Gipp , IMO, isn't really a credible source, to any outside of the movement. I'm not so sure that he would know about it, if there was.
For a man with a doctorate. Dr. Gipp shows quite a lack of research in many parts of his "Wrong Answer Book". One example is his trying to attribute the "Easter" goof in the KJV to the supposed worship of "Astarte", etc. to Herod, a totally-false supposition. Like other KJVOs, Dr. Gipp must be inventive in creating excuses to attempt to support the KJVO myth.
And while there's no "official" KJVO org behind the movement, there are enough KJVOs spread around to create dissent in many congregations. KJVO is one of Satan's success stories, as it has Christians at loggerheads with each other, and casts doubt on many perfectly-valid English Bible translations.
Because of this, part of our work as Christians is to work against the KJVO myth and other false doctrines. Unfortunately, it seems a larger percentage Baptists subscribe to KJVO than do the members of any other large, legitimate denomination. Thus, we Baptists have double duty to try to cleanse our congregations of this pack of lies.
And, back to the OP...as I told John of Japan, it seems the KJVO movement received a large boost from BAPTIST Dr. D. O. Fuller's 1970 book,
Which Bible? and again, I believe many people said to themselves, "Fuller is a DOCTOR; therefore he knows what he's talking about", thus causing a number of people to believe the KJVO myth without bothering to check out the VERACITY of its salient points, its overall falsehood, its dishonest, man-made beginnings, and its total lack of SCRIPTURAL SUPPORT.