I mean in the sense that people used to have to order a Rolls Royce and then wait for it to arrive?

Pateks seem to be all over the place now, even on ebay, but for some reason I'm remembering that in the past you would have to order one from an AD and then wait months for it to be made and delivered.

 

Sometimes I wonder what is that one watch that we (living in 21st century) should stock up, so that it would be the PP of 2050