Well done looks really good, to STOP heat build up when drilling a blank try DNA sprayed from a plastic squirt bottle straight into the hole and on the drill bit while drilling, use a plastic container to catch the drips and reuse the DNA,remove all the big leftover turnings then put a rag over the top of the plastic bottle, push the rag down into the bottle a bit then tip in the old DNA back into the bottle,The rag will strain of all the small leftover bits.