C. 1940s-50s I believe, and probably the topper to a display rack, with a narrow lip along the bottom edge. For me, there is a sort of instant cheer that goes along with the thought of having a greeting card ready for any occasion that might present itself; this seems the right one for the perpetual problem solver, ready to meet the moment however is required!
13 5/8" x 4 3/8". General aging and rusting to the surface as evident.