Combine first 5 ingredients in a small bowl, stirring well; set aside.
Remove giblets from hen; reserve for another use. Rinse hen under cold water, and pat dry.
Place 4 oregano sprigs and lemon wedge in cavity of hen; close cavity with skewers. Tie ends of legs together with string or cord. Lift wingtips up and over back of hen, tucking wingtips under hen. Place hen, breast side up, on a rack in a roasting pan coated with cooking spray. Brush with oil.
Place hen in a 450° oven. Reduce heat to 350°, and bake 35 minutes. Brush hen with half of honey mixture; bake 10 minutes. Brush with remaining honey mixture, and bake an additional 10 minutes or until hen is done. Transfer hen to a serving plate. If desired, drizzle additional honey on serving plate, and garnish with additional lemon slices and oregano sprigs. To serve, split hen in half lengthwise, using an electric knife. Remove and discard oregano sprigs and lemon wedge inside hen.