I like both ideas but add to them:
3. Copies the properties of X weapon without destroying it and it will keep the Arendal none trade able but still the same system. Success wont destroy the weapon just a copy paste of the options. Failure will delete any option in the Arendal but the weapon stays without change.
With this option player can change Arendal stats as they want without loosing said expensive weapon. Press, Success option stones and/or crones will be required for said system.