I found some tissue paper in the closet and moderately stuffed the lower hull as a test. Wow. Cut the noise in half. Now to find something more permanent for the lower hull and move the tissue up into the turret. I'm thinking some floral foam board that I can carve into any shape I want and easily lift it out in one or two pieces. Also no worries about it getting caught in the fan or the gears.

Thanks guys.