Here is where you will want to add a third hole.
Chuck up your #70 drill in the pin vise and get ready to drill. Eyeball the location where you will put the hole and give the drill a few twists. The drill will cut very slowly. Have a look at your start location and adjust accordingly. You can shove the drill around quite a bit before you are really committed. Once you are happy with your placement, start drilling. It will take about a minute to slowly drill all the way through. Use light pressure and keep the chips clear.
You can see that I started a bit higher and then moved to a lower position. In truth, anywhere in between this final location, and the mark left by my aborted start will be fine. The important thing is to aim carefully once the hole is started, so that it comes out in the right place. You are shooting for just overlapping the second, on the vertical axis, the way that the second hole overlaps the first hole.
In this case, I angled the drill upwards, only slightly, and it came out perfectly. See the next picture...
