So, this came out of a discussion on r/occult not long ago, sparked by someone asking why no works on magic refer to any angels as "Duchesses" (possibly because (a) the view expressed by Trithemius in Liber Octo Questionum that good angels never appear in female form was widely held, or (b) there was an established system of Angelic Hierarchies from the works of pseudo-Dionysius, so no impulse to apply European feudal titles to them like there was with demons).
Anyway, one of the commenters on that thread drew my attention to the Pauline Art of the Lemegeton depending, not merely on Jean Belot's Oeuvre des Oeuvres, but more specifically on the 1671 second edition of Physiognomie, and chiromancie, metoposcopie, &c. &c. &c. of Richard Saunders, large chunks of which are barely-credited English translations from Belot's works. Specifically, the table of Hebrew letters which forms the basis for the names of the angels of the degrees of the Zodiac varies due to printing errors over the various printing of Belot's works, and was further changed by Saunders, and according to Alan Thorogood in the Teitan edition of the Pauline Art of Solomon, the names in the Lemegeton are more consistent with Saunders.
If this was indeed the source, this would push the earliest possible date for the Lemegeton existing as a compilation to six years later than the date I claimed in my notes on the Goëtia.
On the other hand, with a closer look at the Ars Theurgia-Goëtia, I have to concede that the work, or at least its scheme of spirits and aspects of its praxis, probably existed in some form prior to its being incorporated into the Lemegeton. In Sloane MS. 3824, fol. 53-71, is found "The Second Parte of the Art of King Solomon," an incomplete copy by Elias Ashmole of a magical work with the same scheme of spirits as the Theurgia-Goëtia. This copy omits the lists of "Dukes" under each chief spirit, as well as practically all the spirit seals (the text indicates they were in Ashmole's source but not copied), and cuts off in the entry for Cabarial.
Crucially, this omits the references back to the Ars Goëtia found in the Lemegeton text: the passing reference to the "garments and other materiall things" at the end of the introduction, and the instruction to "make a circle in the forme as is shewed in the book Goetia" in the rubric of conjuration that follows the description of Pamerisel. The latter instruction, indeed, is also omitted in Sloane 3825, and also makes little sense in the texts in which it does appear, as read literally they imply that you make the circle then go and do the ritual somewhere else with a crystal set on the table of practice. Further, it has a completely different form of conjuration, repeated at length for each chief spirit. This conjurations does not have the blatant dependence on the Turner Heptameron found in the Goëtia ("by the name PrimaUmaton, who commendeth the whole Host of Heaven" parallels an expression in the "Exorcism" but is differently worded to Turner's rendition). Some expressions suggest the English of Dee's Claves Angelicae ("come away"; "move, descend & appear"; "him that liveth for ever") but, compared to the borrowings in the "Invocation of Angels" texts these are short and inconclusive).
(I will also remark, that while the rubric of conjuration in the Sloane 3824 text makes no mention of a circle and refers only to a "Christall Stone or Glass Receptacles [sic]" set on the "Table of Art," the conjurations generally call on the spirit to appear "here before this circle." Amenadiel and Padiel are called to appear "before this Christall" at one point in their conjuration and "before the Circle" later in the same text. I am inclined to regard those two instances of "Christall" as a slip; other conjurations of the period based around evocation to crystal tend to call on the spirit to appear in the crystal or glass rather than before it.)
Since the latter half of "The Second Parte" was not copied into Ashmole's "Longobardus" notebook, and no other copy is known, it is unclear if there is anything at the end of the spirit catalogue, where the third reference to the Goëtia in the Theurgia-Goëtia is found (for the procedure to be followed once a spirit actually turns up).
It is thus by no means certain that the "First Parte" implied by the title is, in fact, the Ars Goëtia; it was possibly some other Solomonic text, perhaps even pre-existing and completely unrelated (e.g. a Clavicula Salomonis version) but which the writer of the "Second Parte" wanted to ride off the success of.
