Beautiful knife! Congrats.
For drilling the hole, make sure you have the hole marked properly (with the ferrule firmly against the saya). I would then put a piece of cardboard or folded paper into the pocket ofthe saya where you will be drilling. Hold it tightly against a scrap piece of wood, like dreamsignals suggested, and drill nice an steady, so you don't get any splintering. Masking tape would help as well.
Again, great knife!