Ring with 4 old-cut diamonds

Ring with 4 old-european-cut diamonds totalling ca. 1.4 ct, ca. WHITE-LTW (H-J)/SI-I1, set in platinum, YG 18K, 7.0 g, RW: 58, 1st half 20th century, minor signs of wear, half ring band presumably renewed, 1 diamond with open notch (natural) in the crown.