Small alteration on a 4x5 Gowland

Looking through people's work on home made cameras got me thinking this is the place to ask about modifications. You folks do some impressive work, btw. I own a pocketview Gowland, made of anodized aluminum, and the back frame has rounded corners, which yield rounded negative corners. This effectively reduced usable neg area, as well as messing w your framing. So I thought of filing down the corners tto make them square, but was unsure what tool to use. I figure aluminum is soft enough that a metal file should work, and then I'd just touch up the paint w a black marker. It's a standard spring loaded back. What do you think? (I'd post a digipic but my wife's camera is full at the moment.) Thanks,

GB

Being aluminum, I would pick up a set of small needle files and work slowly to get the desired corner shape, I know I seem to have to round the corners a bit more on the pocketview, that I do on other cameras when I make a screen for them...but with a proper set of needle files shouldn't take to much time and they will give you the control you need over a larger file.

Dave