This is a crisp like new set with the boxes and all items except the wires for the track bundles, the battery and the envelope that held the lockon and wires. The grease would have been inside the powered A unit box. A battery is needed to run the horn. I think the battewry was also inside the A unit box.
Here's pictures of the poster:
This set was used for Christmas in 1951 and 1952, and then packed away. Over the years people opened the box and examined the cars to see what was in the box. The locos were in the bottom of the carton so they weren't touched. The son lived in the house the parents had bought in the 1940s until a few months ago. The trains were found in a closet when the house was cleaned out.
I used to find gorgeous trains like this frequently. Now, not so often.