I picked this wall rack up years ago, you can stack another rack on top of this rack as there are holes. Rack is made of wood with metal edges. There is a heavy locking bar (not shown in photo) that will lock both rifles and carbines. It is very difficult to find any photos in reference books that show this rack. I believe it is WW2 as indicated by the drawing number. Only M1 rifles or M1 carbines will fit.Attachment 87449Attachment 87450Attachment 87451