If you mean a servo from a 116 chassis 450SE/SEL then the answer is yes. The 126 chassis 450SE/SEL uses an entirely different system. If you replace the servo then chances are you're going to need the amplifier as well. What is the year of the donor car?

The 116 chassis servo is actually a different part number than the 107 chassis version (450SL) but the difference won't affect the performance of the system. Worst case the temperature set on your thumbwheel would shift by a few degrees.