And before then the 4.5V 'blue' rails (you could upgrade from that to the 12V system by swapping out the motor and adding the middle rail, but that lost you the ability to make certain tracks because then the two rails would end up being shorted out, which is why Maerklin long ago decided to use a center track for one pole and the outside for the other).
I have train set 182 [1] from 1975, bought at Harrod’s in the UK and brought back to the US for a family friend who passed it on to me. It’s still in the box with styrofoam liner.
Oh, it was definitely used, but appears to be all there. It's notable in that the set comes pre-assembled and in the styrofoam packing, which is how I received it. I can only imagine what new would look like.