Logitech C905 Grip Mount (not-threaded)

Have not printed yet as this is not quite done being modeled. What I need is to have a threaded hole put in the base of this that fits your standard 1/4" tripod mount, but I lack the skill to do so.

I used Google Sketchup since that's currently all I know how to do, and the grip part is based off of the model made by TheRealNecator (thing:2464087). I can't get some parts of the model to be... Not internal, if that makes sense. Where the outside is white and the inside is gray, parts of the base on the outside are still gray.

If anyone feels up to the task of creating a threaded hole for me in this design, please let me know and I'll provide you with whatever files/details I can to help!