Antique brass Postal Scales.
Mahogany base. Only 2 out of 5 weights present.
Base: 8.75 x 4.5 inches;
Height 4 inches.
Weight: 700g (allow 1.25 kg once packed).
The 2 weights present are: 4oz and 1/2 oz.
Reasonable condition for its age - 3 weights are missing.
See video below for mechanism: