My guess would be sugar bowl, though powder jar also seems a possibility. The patent was issued to Gloster, Ltd. on Feb. 28, 1930 and, interestingly, actually applies to the process of covering the Bakelite-type base with thin sheet silver by a spinning technique.
~Cheryl
Abstract of GB325841
325,841. Gloster, Ltd., J., and Gloster, L. J. Nov. 30, 1928. Condiment receptacles; drinking - vessels; sugar basins.-Hollow articles of the kind commonly spun from sheet silver or other metal, such as salt-cellars, cups, sugar basins, vases and the like, are made by covering with a thin sheet of the metal a moulding of the required shape made from a plastic material of the formaldehyde condensation product type. The moulding may be formed with ribs, grooves, or similar ornamentation, which will be re-produced in the finished article. Fig. 2 shows the construction of a salt-cellar. The moulded inner part a, formed with a lip or mouth rim b and a base ring c, is closely covered, by spinning, with a covering d of thin sheet-silver as far as the underside of the lip, a separate flanged ring e of silver being spun over the lip portion to complete the covering. The articles may be composed of two or more mouldings fitted together and covered by sheet metal applied in one or more pieces. Specification 20162/05 is referred to. http://v3.espacenet.com/textdoc?DB=EPOD ... 325841&F=0.