This is the mounting bracket for the 200mm Scan on which certain jigs slide directly. The Sliding Guide also fits onto the Saddle and in turn certain other jigs slide on the Sliding Guide.
Blade, Plane, HOCK, HIGH CARBON O1 Steel, for Stanley STANDARD ANGLE Block, #9-1/2 & #220, built POST 1985, 1-5/8 wide with 7/16 INCH WIDE SLOT, #BL162, #19P2081