Dustin, can I make a suggestion here? If the fan blades are caked in dust, there is an easier way to remove it. Go ahead & take one of your Kirby's, set it up in blower mode, & put the crevice tool on the end of the hose. Then use it on the motor, & you'll be amazed at how much dust you will get out of it.
I found a Eureka Maxima bagless vacuum last year that had a loud motor & poor suction because of dust buildup- blowing out the motor cured it & made it much quieter & restored it's power! I have also found that you can extend the life of exhaust HEPA filters if you blow them outside with a crevice tool on the end of the hose to concentrate the airstream.
Hope you get your Princess back up & running well.
Rob