If you look carefully you will notice that some of the holes at the six o'clock position (in the image) are a bit dodgy.Here is a close up-
They are elongated. These holes are 0.4mm Dia. The problem was that I had allowed the drill bit to project too much out of the drill chuck. A 0.4mm bit will certainly flex when you drill brass.Here is a closer look at the offending holes-

There is nothing else for it but to start over. Silly mistakes can sometimes cost an entire days work.
Aditya
