Truth its that I have not read a lot of the old Grimoires,because 1) english is my second lenguage and one thing its reading and speaking english and another is reading Ye olde English, second most of the old stuff I have it in digital format which hurts my eyes to read for long, While I have a copy of the Trve Grimoure, which its Jake Stratton Kent’s work on the Grimorium Verum, The Black Pullet, Key of Solomon, Abramelin, Honorius,Legemeton, etc.and other books that deal with the old stuff in some plain new fashioned writing by authors, still most of the basics of the books probably its covered all over dozens of books, or there are specialized books on that, still if you have acces to copies o comentary on old grimoires you can always enrich your expirience with that, noting also the most grimoire were written in a semi cryptic manner so the uninintated would not understand, and the old secrecy ways made it hard to make a take on the magus that precided us, also I dont read a lot of the old stuff because a lot goes by Lodges and secret societies its hard to know everything they talk about without being given a clue somewhere else, the important matter here is that is unlikely that one grimoire or book will satisfy all knowledge you could want for your magical prectice, so Im just going to drop a List of books on that should be on your read list, note that this are classical books of magic, check out DB Publishing at the top or Official Melissa Press for Demonolatry Grimoires if you haven’t already.
Astrology: Picatrix Al Hakim or the Goal of the Wise
Three Books of Occult Philosophy – Henry Cornelius Agrippa (cornerstone in the occult libraries)
Franz Bardon – Initiation Into Hermetics
Not so Old but very helpful: Secrets of the Magickal Grimoires: The Classical Texts of Magick Deciphered by Aaron Leitich
This should give you a head start where to begin with in many aspects, Peace out.