Antique Georgian oil painting on glass portrait of the Nativity

Antique Georgian oil painting on glass portrait of the Nativity. English School, circa 1800-20. Unsigned, artist unknown. Painted on the reverse side of a panel of glass. Wooden frame. Size of frame: 16 x 12 inches; Size of back panel: 14 x 10 inches; Size of front portrait aperture: 13.5 x 9.5 inches. Weight: 936g (allow 4 kg volumetric weight once packed). Condition commensurate with age - various superficial marks & scratches, some bubbling of paintwork to edges and corners and some knocks to wooden frame but all part of its charm and character. Priced accordingly. Apologies for glass reflection in photos.