Once Salomet is defeated, he will drop the Wyrmking's Ring near the cliff's edge. Pick up the ring, and any treasure and return to Aldous.
I'd say focus on dragon forging anything that comes from cursed items. You can get a near always level 1 armor or a bit more rare a level 1 weapon in the room with the chained cyclops. If you get the uncursed leg item... unless it is a big improvement... reset.
No. The Wyrmking ring will stack with Articulacy but holding two rings will not provide any additional benefit.
In order to obtain The Knave achievement/trophy, the Arisen must acquire a forgery in some way. One method is to request the duplication of a magickal item from Mountebank at The Black Cat. An alternative method is to obtain a Wakestone Shard Forgery, which can be found in a chest in the roof attic above The Black Cat.
Despite being a ring, this item cannot be equipped; its effect is active merely by holding it in one's personal inventory. The effect stacks with the augment Articulacy to reduce spellcasting time by around twice as much. Multiple rings in personal inventory do not stack the effect.
The Wyrmking's Ring is a useful item for spellcasters, and can be forged, allowing the quest to be completed whilst retaining the benefits of the ring. However the Wyrmking's Ring Forgery will not function correctly when Edmun attempts to use it to get the Paladin's Mantle from the Treasury room chest.
Rather than requiring materials and a merchant, dragonforging can only be achieved by slaying a Dragon. Upon the death of a dragon, all armor pieces and weapons the Arisen has equipped have a chance of becoming dragonforged.