My map has the wrong spot marked, others may have it wrong as well. The loc posted here is correct. He is Southeast of the spot my map had marked. Here's the updated spot for your map:
P 1120.4862, 2089.6887, 24.4978, 0, 240, 0, 2, Tavin/Ezna_BST/SHM_Spell_Vendors

Spell: Diregriffon's Bite