Camera lenses.

E.g. the mid-70s are half a century ago but these old lenses that are just metal and glass - they'll last forever. Just buy an adapter and let's go. They aren't as fast or as compatible with autofocus with new mounts that change every 20 years - but people feel nostalgic for the rendering and looks of old lenses. They'll feel nostalgic for our modern lenses in another 50 years too.