This item is a mechanical wind up train engine from Kanto Toys. This engine is all plastic except for the key but part of it is made to look like metal. It winds up on the side and when given a little push runs on the floor. It has a label on the side with the number 1630 and a label on top is written in Japanese. It is marked on the bottom Kanto Toys Made in Japan and has a series of 3 patent numbers. I believe this toy is from at least the 60s or 70s. The engine measures 7 1/2" long, 3 1/2" high and 3 1/2" wide including the key.
This engine is in good shape but does have places where the paint has been worn off. Please ask any questions before purchasing.