This is a beautiful art deco design, of hexagonal form. It has depth and complication to the design, with the asymmetric 3 pointed internal layout. 
It has a dark brown Bakelite base which is an added layer of intrigue to the design. 
The hallmarking is from Birmingham assay office, dating to 1933. The hallmarking is slightly rubbed, but is still legible. 
It has an engraving of the initials S.M.B to one of the faces. 
S Blanckensee & Son Ltd were a quality silversmith based on Frederick Street & Great Hampton Street, Birmingham. 
It is in decent vintage condition. It has a dimpled dent to the inside and spots of corrosion due to ash. It can be polished, but it has been left as is for the next owner.
Dimensions:
Width across flats: 87.5mm
Width across points: 100mm
Depth: 18.4mm 
Weight: 137g