Very good bike saddle factory tour video
I love factory videos and this is a really good (very long) one. It shows the process for making Brooks saddles - the metal and leather bits both - and comes from a very popular Japanese bike shop/brand kinda entity, Blue Lug.
Brooks saddles are extraordinarily long-lived objects - you can find many-decades-old ones for sale on eBay. If you maintain one well, it will last practically as long as you do.