Automatic Direction Changer

What there is most of

• Train Direction Switch - 4.5V 2 x 3 · White×4
• Electric Train 4.5V Automatic Pole Reverser Brick 4 x 9 with Magnet Holder and Small Blue Train Magnet · Light Gray×1
• Plate Special 2 x 4 with Train Coupler Open with Magnet Short Cylinder Red · Red×1
• Wire with 4 x Blue 1-prong Connectors 4.5V, Hollow Pins 15L · White×1

The twenty most numerous parts, longest bar first. Start a checklist to see all 4 part types and tick them off as you find them.