Antique buying blue on white hand painted plate

Hand painted ceramic plate, bird motif with flowers, blue on white background. The plate has scalloped edges with a "wheel" design. On the back are painted blue flowers with blue leaves going around the edge of the plate. The trade mark is hand written V.A.O. Coimbra Si Sec - XVII. Coimbra, is an inland city in the center of Portugal north of Lisbon. The Sec XVII means seventeenth century. The scalloped edges are unusual and the plate itself is a collectors item.
The plate measures 10 3/4 inches in diameter and weights 1 lb. and 13 oz.