Thanks all! The two-headed Ash and the Necronomicon on its pedestal are both Army Of Darkness figures by Leading Edge Games (sculpted by Sandra Garrity), they are not conversions and used as-is. They seemed a bit like 25mm but I've found that they fit in quite nicely with my undead models, which is a big plus. They have quite thick integral bases and I've glued them to the slotted bases with integral bases and all (same goes for the skeletons BTW). The skeletons are all from Ral Partha, I really disliked some of them at first but the one on the left in the foreground and the one with the halberd are both very nicely detailed, and painted up they look quite nice together as a group.
Edit: I still think your entry is awesome Achab! Had your entry been new it would be a much closer match, well done!