OK, so, this is my summary, there are two types, the all-horn core and the wood and horn core. The all horn can be split into cores using two layers, which I suspect are made of off-cuts, and cores of single layers. The horn and wood cores might be earlier or a more north/west type, the all-horn may be a more central European type??? Ibex is the preferred horn but baleen is better. Wood cores usually identified as oak are almost certainly yew.
Horn and wood cores use yew in the centre having chased a ring and tapered the lath as in every self-bow, the sinew laid over the curve of the ring in a way every bowyer recognises in a minimum of 3 layers. The belly lath is really convenient for tillering as it tapers like the belly of a self bow and can be scraped for a sweet curve in a way that horn isn't. The two timber layers sandwich a tapering horn bar forming a box girder type thing but the bottom layer is slightly wider than the horn to receive the sinew.
Now, the ends of the prods are held together by a 4.5" horn wedge with a knob on the end, which goes right through the box beam and sinew and is itself reinforced by three horn wedges forming a reinforcing second layer at the tips. The knobs are carved for the nocks and covered in pitch