AN HISTORIC ROYAL PORTRAIT MINIATURE BROOCH, BY KOECHLI   The two miniature portraits of HRH Prince Nicholas of Greece (1872-1938) and HI and HR Grand Duchess Elena Vladimirovna of Russia (1882-1957) commemorating their wedding in 1902, within a rose-cut diamond border to the heart-shaped vari-cut diamond frame, 4.4 cm. high, with Russian assay mark for gold  With maker&#x27;s mark for Friedrich Koechli (1839-1909) #Royal #jewelry