Here is a question for the Fairbanks-Morse masters: I have a Model Z 6 HP at 550 RPM engine with a 7-inch bore. All the information I can find only shows the Z engine being a 10 HP. This engine was found in the basement of a building in Lowell, Mass., used to stamp out brass buttons. Does anyone know the color of this unit? Can any of the readers help? N.D. Monaco, 10 Arlene Ave., Stoneham, MA 02180; (781) 279-4543.