I think do not make the hole near the transformer. Better to make near to face because there PS output is purest we can get there and we need not take those near transformer again. Better make it where output of PS is. Transformer side is input to PSThanks Magma,
Please refer this pic,hole size is 10mm.I will also need B1 holes close to input/output as I am not going to use input selector.
[URL=http://imageshack.us/photo/my-images/204/p1000647bo.jpg/]Uploaded with ImageShack.us[/URL]
Regards,
Sachin