This header consists of a printed display card glued to a rectangle of tinplate. The tinplate edges are bent back to clamp it to a wire-frame display rack.
9 3/4 in
The header shows the same photograph as the Space Station set box, in identical size. This could indicate that the artwork for producing both box and header came from the same production studio.
Whether Triang/Rovex distributed entire display racks or just these headers isn't known. The example shown was found in Finland.