Is the Hitec HS-422 Servo still constructed such that the motor and pot are connected to the board with wires (as illusrated in the below how-to link) instead of direct soldering to the board? I’ve recently opened a Hobbico CS-61, TowerHobbies TS-53, and a Futaba FP-S148, and all are directly soldered to the board. If the HS-422 is still connected with wires, then it would serve as an easy platform for doing some servo hacking and modification.
I believe this is still the case. The HS-422 is one of the first servos the Open Servo guys used for their experimentation, and they are still working with it.
8-Dale