It does come with the bottom battery cover. I took the picture without it to show there's no corrosion.
Two buttons on top for a couple sound effects.
The grain arm chute can swing out.
Rotate the end knob on the grain chute to move whatever is similar to grain you put in there.
The front black grain reel rotates as you push it along the floor.
Various wear:
Missing the right-rear side panel. The side with that black circle area. Looks nice without it, but it's supposed to be a hinged panel.
Rotate the knob on the top back to turn the back wheels. The knob mostly works, sometimes skips a gear tooth or something.
A rear wheel is a bit bent. It's on there and works, but sits at an angle.
The black grain reel is missing almost an entire row. Some of another row is separated from the main part. It works and I would say isn't overly obvious from casual viewing. Could glue or black ziptie/twist-tie them.
The front hinges on the main body where the reel section attaches has a couple broken tabs on one side. The reel still attaches fine and sits on there fine. The top of the reel part hooks over the top of the main chassis part, and the two reel tabs hook into the metal ends sticking out.