The servo rudder you are looking for is here, all sizes and mounting types are available!
Reference 08293404
Brand: HUDY
ALU CLAMP SERVO HORN - KO PROPO, SANWA - 2-HOLE M3 - 23T - 293404
Reference 08293444
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - KO PROPO, SANWA - 2-HOLE - 23T - 2934
Reference 08293446
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - FUTABA, SAVÖX - 2-HOLE - 25T - 293446
Reference 09C-10112
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - S MALL - 21 SPLINE - NOVAK NES-1 - C-101
Reference 09C-10113
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - SMALL - 23 SPLINE - SANWA - JR - C-10113
Reference 09C-10122
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - LARGE - UNIVERSAL - DOUBLE END - C-10122
Reference 09C-10123
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - LARGE - UNIVERSAL - NARROW END - C-10123
Reference 09C-10124
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - H D LARGE - UNIVERSAL - 23-24-25 - C-101
Reference 09C-10131
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - SMALL - 24 SPLINE - HITEC - C-10131
Reference 04SRT-TRX5
Brand: SRT
2 holes 25T SRT steering servo horn - SRT-TRX5
Reference 05FAST310B
Brand: FASTRAX
23T BLACK ALUMINIUM SERVO HORN (KO/SANWA) - FAST310B
Reference 08293421
Brand: HUDY
ALU CLAMP STEERING SERVO HORN - EXTENDED 8mm - 23T - 293421