I know my wife's 1991 911 isn't exactly an "early 911" but this one may be one for the books. The rear HVAC blower began to howl, indicating bad bearings. Rather than buying the entire assembly, I ordered just the motor from Pelican Parts. Upon disassembling the blower, I finally removed the impeller. Apparently, it looked like an excercise wheel to a poor mouse. It's dried-out body was stuck to the inner side of the blades. My wife was wondering when the mouse was running on the "exercise wheel" if she was getting one extra "mouse power?"