Vintage Brass and Marble Abacus with Instructions

Vintage Brass and Marble Abacus with Instruction Booklet Comes in the box but the lid is missing, only bottom of box is included - booklet has some wear/tear on the front cover. Measures approx. 3 1/2" x 2 1/2", the counters move freely, weighs almost 9 oz. There's some glue residue around the brass, please see pictures - normal wear to the brass from use and age Great vintage item.