For sanding, the top of a table saw works well also.
Instead of WD40, it's petroleum base may affect the insulation on the windings, how about recommending CRC 2-26 or a similar product made for the application. The CRC product is available at Home Depot. Here's a link.
http://www.crcindustries.com/ei/cont...=02005%2D6&S=N
Also, the grommet plugging the spare hole in the cover will shrink quite a bit if hit with carb cleaner. You can guess the results.
I wonder if after plugging the bottom vent hole one should add a vent line to the area?