Because of the way both morphs & animations work, I not only had to use a stock mesh (or be forced to redo the egm and tri files ALL OVER, and honestly, the ONLY person I know of who has ever reportedly even tried doing that was throttle kitty (one of the highly experienced elderscrolls modellers) back in oblivion), but I couldn't add or remove any vertices, because that would re-order the vertices and cause the morphs (in the tri file) to go bonkers. I would have preferred making my own from scratch, but... it actually turned out nicely in the end, despite the handicap.