NY -- Standard&Poor's CreditWire 10/16/98 – Standard&Poor's today assigned its double-'A'-minus rating to Watertown, Mass.' GO bonds dated Oct. 15, 1998 due Oct. 15, 2017. The bonds are scheduled to sell Oct. 26, 1998 In addition, Standard&Poor's affirmed its double-'A'-minus rating on the town's outstanding GO debt. The rating reflects: -- A sound economic base, in close proximity to Boston; -- A trend of sound financial performance; and -- A moderate debt level. Watertown is a community of 31,000 that borders Boston, with a base primarily oriented toward retail and manufacturing. The Arsenal Mall, a center with 1,174 jobs, and Watertown Mall, a complex employing 500, are the top employers. It is on the