Pair of Square Silver Plated Decanter Coasters circa 1830-40

Description

A pair of silver plated square decanter coasters; they are unusual because they are square in form and they have a top plated metal base with an underbase of felt lined wood.  The coasters have gadroon borders, one of which has lifted and there is a small dent on the same coaster, as can be seen from the photos, and both have worn (from cleaning) fluted borders with a base of four concentric circles; there are discolouration marks on the plated bases.  The coasters have no makers marks as far as I can tell and my speculation is that this pair may have been an apprentice piece or perhaps a bench test of a potential employee; they must have been of sufficient quality to be plated and polished.
Dimensions are approximate
:
Height: 2", 51mm
Length & Width:  5-5/8" x 5-9/16", 143 x 141mm and 5-11/16" x  5-1/2", 145 x 140mm
Weight:   1lb 8 ounces, 684 grammes