Eldritch refining manual or a lost machine?

Question

A legendary craftsman known for refining Eldritch items for the purpose of what special refinement he can bring to the items, is there a refinement manual or a lost machine for such a forge?

Answer 1

No, there's not. Gnomaurum is just a lore character, the NPC does not exist. The same goes for the "refining" process, since the Gilded weapons are dropped by The Brainstealer just like the regular Eldritch Weapons.