Back in 1981 i got a pair of HD-400 for my 15th birthday, and i still have them today, but i did have to change the earpads a few hundred times over the years.
Aside from my Grado HP1000s, i don't get very exited about vintage headphones, or speakers for that matter, i find that they often don't age very well
I'm holding on to my 400s for sentimental reasons, because in my opinion, my little Grados SR80is sound so much better, it's not even funny.