[Boatanchors] Chassis Mechanical Question

[whitebear1122 at comcast.net]

Greetings.  I have a mechanical question.  I am in the process of drilling , milling, and hole  punching several chassis's fo r my HBR-13 receiver project.  I have all the holes punched except for three octal socket holes.  I just discovered the octal ceramic sockets require a 1 1/4" hole and my Greenlee punch is 1 1/8".  My question is this:  Can I realistically file 1/16" all the way around with a rat tail type file and have the hole look clean.  I'm worried I'll start filing and it will end up looking like crap or become  goofy shaped.  Is there some sanding barrel shaped attachment for a drill that would open the hole slightly and evenly? 



I wonder if anyone has a used Greenlee 1 1/4" inch punch for sale.  I've got a nice selection put together so far, including  5/8", 3/4", 7/8", and 1 1/8".  I've never used a punch before this and they have been fabulous!  I did have to learn a lesson though.  I was so darn careful to be precise in my layout drawing, and transferring those hole dimensions to the chassis.  I used the recommended punch screw hole dimensions in the Greenlee instructions and then found out the holes didn't need to be that big, so the punch floated around too much and all the tube socket holes are slightly offset. Darn.   Maybe it'll look better when I take the  masking tape off.   :)    



Thanks.  73, Sc ott WA9WFA