Important icon from central Russia, 19th century

Important icon from central Russia, 19th century.
"Saint George the Great Martyr".
Tempera and levkas on panel.
The saint is framed by a copper 'basma' and surrounded by an inlay of 16 miniature icons in copper, bronze and enamel.
Measurements: 72 x 58 cm.
The interest of the icon in question lies especially in the inlay of 16 metal icons surrounding the central motif of St. George. Dating from the 18th century, their creation may have been due to the fact that, originally, there may have been pictorial scenes from the life of St. George that were partially erased. For this reason, the decision was made to replace them with metal icons. After a detailed study of the piece, the conclusion is drawn that the substitution may have been made by the Russian Old Believers: during the 18th century, the Russian government prohibited the creation of metal icons and confiscated those that already existed. Many historians believe this was an effort to divert metal for military and minting processes. Inevitably, the Old Believers became the main target of this ban because they were the main makers and users of metal icons, which had great value and importance in their households. The ban on metal icons lasted well into the 19th century. The sheer number of icons that were lost or seized during this time made metal icons such as the one in question less common and more valued in today's art market.
The icon in question, with the depiction of St. George at its center, is outlined by a copper "basma". The basma was the first form of ornamentation of icons. It consisted of sheets or strips of metal engraved on the surface of the icon, not as a single piece, but as a series of pieces forming the cover.