Where does NOS come from? I'm always seeing 20-30 yr old campy stuff on ebay thats apparently new. Were the 70s/80s a good time for hoarding fancy bike parts. I just find it hard to believe that bike shops couldn't find some opportunity in say, 1987, to sell that brand "new" derailleur sitting in the back.
Similarly, what parts should I begin stashing in my basement for 2030?