Up for auction is a VERY RARE Original NOS American Flyer HO gauge train car box.

I could not find an example of these HO scale flat folded boxes anywhere on the internet. 

This box has never been folded into its box shape and has never been stamped with a car model. There is no copyright date on this box, but it was manufactured for the AC Gilbert company in the early 60s. The model #B4N066-M5348 is stamped on one end.

flat it measures 10 1/2" x 3 1/16" and folded it would be 5  3/4" long 1  5/16" tall and 1  3/4" wide.

The white parts are very slightly yellowed and the red along some of what will be the corners of the boxes is slightly rubbed off, but, is is a 60 year old cardboard product.