As it turns out I did crack the window while adding countersinks to the holes. I quickly stop drilled it and moved on. It is center forward on the top so I will be able to see it every time I get into the plane. It was a needless error. I had a technique that was working well and decided to try something different on this hole to save a step. I knew better.

Then the window came off for it’s very minor trim and edge polishing. I could also dimple the skin now that the holes were drilled.