The servo rudder you are looking for is here, all sizes and mounting types are available!
Reference 08293445
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - HITEC - 2-HOLE - 24T - 293445
Reference 08293447
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - KO PROPO, SANWA - 2-HOLE M3 - 23T - 2
Reference 08293448
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - HITEC - 2-HOLE M3 - 24T - 293448
Reference 08293449
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - FUTABA, SAVÖX - 2-HOLE M3 - 25T - 293
Reference 08293491
Brand: HUDY
ALU SERVO HORN - KO PROPO, SANWA - OFFSET 1-HOLE M3 - 23T - 293491
Reference 08293494
Brand: HUDY
ALU THROTTLE SERVO HORN - KO PROPO, SANWA - OFFSET 2-HOLE M3 - 23T -
Reference 09C-10114
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - S MALL - 25 SPLINE - FUTABA - SA - C-101
Reference 02RC15202-BLK
Brand: RC PARTS
ALU CLAMPING SERVO HORN BLACK (25T - 19mm) - RC15202-BLK
Reference 02RC15202-BLU
Brand: RC PARTS
ALUMINUM SERVO HORN BLUE (25T - 31mm) - RC15202-BLU
Reference 08293411
Brand: HUDY
ALU CLAMP SERVO HORN - 2-HOLE - 23T - 293411
Reference 08293414
Brand: HUDY
ALU ADJUSTABLE CLAMP STEERING SERVO HORN - 23T - 293414
Reference 02UR1801
Brand: ULTIMATE
ALUM.STEERING SERVO HORN FOR SANWA/KO 23T (1pc.) - UR1801