You want to make sure that you have enough layers on top of the screw holes so that it holds solid to the DeWalt. So make the top layer thick enough to be solid.
This is the 3rd version of "holders/mounts" that I have added to the air diverter. It holds really solid because the diverter fits up and around the base of the 611 which gives is lateral stability.
You will need 2 x 3mm nuts that fit in the backside of the mount for the 3mm bolts to hold holder to the diverter. Other than that, all the other hardware is spec'd out on @dewitt's model.