This is old . From the design, and that apple-green color, I'm guessing 1940s or early '50s at the latest. Could be even earlier. Three piece cake carrier. Interior of cover will hold 10"x4 1/2" cake. Cake plate is aluminum and says "Carlton Aluminum" with a patent number, 11" x 3/4". The little harness that holds cover and plate together is still tight, no bends or twists. Cover is heavier, tinned steel (holds a magnet), tin has darkened with age. Glass knob top seems original, no nicks, chips, cracks or flea bites. Green background color is worn in places, mostly top and top edge (see photos). The designs were either hand painted or stenciled, you can still feel the paint. These are in good shape, still whole and vibrant.
A true antique, wonderful piece for the collector, but also a great carrier for that next bake sale or pot-luck dinner.
Thanks for looking, if you have any questions, please email me.