They really start from scratch. They mine the ore then use it to make steel to make axes to chop wood. This ensure that the know-how is genuine. They've been a

They really start from scratch. They mine the ore then use it to make steel to make axes to chop wood. This ensure that the know-how is genuine. They've been able to "rediscover" how things were actually made. It's a sort of retroactive proof of concept.