The CS1 conical scalar includes a generic clamp that will fit may dishes, but I don't believe that it will be easily or optimally fitted to the Channel Master 1m design arm with the three merging support arms.
KU bracket is 23mm and too small to clamp a C-band feedhorn. Before disassembling the current clamp and feedhorn, measure the exact placement of the feedhorn.
Use the current clamp to create a new base to clamp the 55mm feedhorn so the center of the C-band feedhorn is at the same height as the center of the current KU feedhorn and the opening of the feedhorn is approximately the same distance and angle to the reflector. The design needs to allow the feedhorn to rotate, slide towards and away from the reflector and allso to allow the CS1 conical scalar to move towards and away from the reflector without contacting the clamp. The scalar placement is highly critical with micro/miniBUDs!