I have no idea if it pulls off but i bet I can cut and put a window at that place as i did with the dm10 grips..
If you can find a spare grip it is worth trying!! just be patient and take your time..
Make a blueprint, copy it onto the grip then make the plexi window and finally cut the grip to fit the window.. also when you are about to glue it in place cover both sides with some tape to avoid permanent fogging of the plexi due to the fumes of the super glue..
It's nothing man, just needs some time and preparation..
Good luck if you decide to do it..