Hallmarks seen on sugar basket crystal with silver rim and handle
These are Polish hallmarks. This additional warrant mark, seen here a bit deformed, of the woman's head facing left within a circular frame-shape, was used on secondary parts added to the main body of a silver item. On articles of mixed metals, the additional silver parts would be indicated by this mark being struck beside the primary precious metal hallmark on the body of the item. This mark was used from 1921 to 1963.
Additional fineness mark used only from 1921 to 1931, these single-digit, quatrefoil frame -shaped additional fineness marks were stamped on secondary components or applied pieces of either gold or silver, in conjunction with the appropriate additional mark, on silver it was beside the circular additional mark. 3 to indicate silver 800 fineness W for assay office Warszawa ( Warsaw). The maker's mark E?C unknown to me.
Source;
World Hallmarks Volume I, hallmarks of Europe 19th to 21st Centuries William B. Whetstone, Danusia V. Niklewicz, Lindy L. Matula 2nd Edition.
Peter.