Gnostic Mass proto-prose in Regardie's Golden Dawn?
I am trying to find out if Book 6 in Regardie's Golden Dawn was written by Regardie or is taken from original pre-Regardie/Crowley GD documents.
If you go to page 417 of Llewellyn's 6th edition of the Golden Dawn, in the chapter called "Consecration Ceremony For Jupiter Talisman" about halfway down the page (417) there is prose that is very similar to parts of the Gnostic Mass-including parts of the anthem and many of the Priests lines.
Is it possible that Regardie wrote Book 6 and that this porse was actually inspired by Crowley? Or is it more likely that this Book and chapter came before AC and that he was in possesion of the book/document and borrowed certain phrases and changed them for the Mass?
Is there any way of knowing the author and date of Book 6?