Vintage Art Deco Silverplate Triple Stamp Box Holder

Description

This is what I believe to be a vintage Art Deco silver plate triple stamp box.
Based on the design, I would estimate it dates circa 1920s or 1930s.
It measures 2 1/4 inches wide x 3 5/8 inches long at the two end pieces (5.7 cm x 9.2 cm). It is approximately 3/8 inch thick (1 cm).
I am stumped as to exactly what this was used for as there are tiny tabs on the bottom, as if it held on to something else.
There are scattered scratches on much of it. It is covered in tarnishing.
Please use the photos as your guide.
It weighs 3 1/2 ounces (100 g).