The order that Kellner and Reuss assembled was a fringe Masonic body offering a ladder of degrees, and its distinguishing claim was that the higher ones taught a sexual secret. Crowley took charge of the British section around 1912, and once he had accepted the Book of the Law as authority he rebuilt the system around it. The degrees remained; what they conveyed changed.
The most public product is the Gnostic Mass, written in Moscow in 1913. It is a ceremony for a congregation with a priest, priestess, deacon and children, and it is performed openly today by bodies in the order's lineage. Anyone can attend one. That is worth stating plainly, because an order best known for a secret about sex conducts its principal rite in public.
After Crowley died in 1947 the succession was disputed for decades between claimants in Britain, Germany, Switzerland, Brazil and the United States. It was settled, in the United States at least, by litigation in the mid 1980s, when a federal court recognised the body led by Grady McMurtry as the successor holding the copyrights and the name. Other lines continue to dispute it.
The point for a reader is that lineage claims in this tradition are frequently decided by courts rather than by initiates, and the documents are therefore public.