Cased Pair of Salter Balances PS37

Pair of original, quality, pre-war, nickel plated tubular spring balances. In the original blue velvet and white silk lined leather look paper covered box, with a hinged lid and a pair of clasps. Both these balances are stamped for the maker "Salter" and the one with the spring clip, presumably for letters, is calibrated in ounces up to 16oz and the other, with a hook for parcels? is calibrated in pounds up to 15lbs. All is in near mint condition, probably not seen action and both balances are complete and in good and working order.