Andover Companies Merrimack Mutual Fire Insurance Wilton-Columbia Pewter Plate. Gorgeous collector plate made by Wilton-Columba PA. Plate markings read RWP and Wilton-Columbia PA. Heavy weight and high quality feel to this collector plate. Please note there is some signs of wear (see pictures), but the plate is in overall excellent condition. Across the face of the plate reads "The Andover Companies 1828, Merrimack Mutual Fire Insurance Company."