Hi,
Isn't that possible to achieve by many different ways?
For example you can add new property to your sword json data called lets say "scene" and then when you want to equip selected weapon you just do something like:
#Assuming weaponData is object from parsed json
var weaponNode = load(weaponData.scene).instance()
Another way would be to assume that "item name = item scene" and then for example if you have weapon data path like: "res://Data/Items/Weapons/test_weapon.json"
you know corresponding scene to load should be "res://Scenes/Items/Weapons/test_weapon.tscn"
. That's less flexible solution because you can't share the same scene among many different weapon data or you need to copy it.