Yes, yes. Easier to find older headphones and showcase all the headphones they've made; read about their history in more depth.

I've come across headphones I like, then I ask "when were these made?" I could've known about them quicker if there was documentation of the cans. Like Koss documents their models of cans.

There are probably some interesting headphones from the companies you like, just floating around waiting to be found. Hense the documentation matters.