Thank you for submitting your item for appraisal. This appears to be just as what you suggested, a silver plated biscuit box, embossed laurel wreath pattern on the hinged lid, incised acanthus leaves or foliage and flowers on the sides, with the company mark at the base. During the victorian era Great Britain ruled the world and its forces successfully invaded foreign countries, a laurel wreath would have been a well chosen ornament. The estimate is based on similar items sold at auction. A serious Sheffield plate collector might be willing to pay more than the high estimate. There is no measurement for the sentimental value you might attach to the item.