I went throught the napa book with my parts guy. Nothing we could find. I talked with Bill at Valley Power Products (540-345-9650). He sells parts and manuals. MT1601 is an oddball. He had a customer use a napa 6257, which fits almost perfect. Then you need to add about 1/8 inch foam weather stripping on one end for a tight seal. I used a piece of wetsuit material on the inside of the housing cover. Looks and fits perfect.