How Hermès Bags Are Made (Vogue Video)

I really enjoyed this video when it popped up on my YouTube feed today.
The part that really struck me was about how they "test" the sounds of the hardware and decide if they like it or not. I loved this so much because the sound of the hardware and the sound of the leather is one of my favorite parts of H bags. I have a swift Pliplat that "squeaks" and it makes me so happy!
 
So they make all bags by hand? I was reading somewhere that only Kelly’s and birkins are made by hand. I’ve even heard only parts of the k/b are made by hand. But I’m thinking that’s not true?