This is the original cover painting for the romance novel by Anna Macklin published by Piatkus Publishing UK in 1995.  (I show the published cover for reference) Beautifully rendered in acrylic and gouache on illustration board , in "wraparound" landscape format, c. 11" x 14.25"  and comes with a label attesting to its authenticity signed by Pether's widow, mounted to the back.  Wonderful style!