You are looking at an original Lionel milk car platform that has been modified to go anywhere on your layout. Wthout the extension, you can even use it with your American Flyer or Marx! or maybe you want to put it with another factory or warehouse building.
This was made to go with any milk car O or 027. The metal platform is adjustable.
However, as you can see, this one is rough--it needs serious cleaning, resotration or repaint unless you need it "weathered".