How to Fix A Busted Metal Edged Box
There is another simple solution involving precisely one other common archives supply and a darning needle. A couple of steps and your box corners will be back together and strong as new. This method works even if the metal fastener has been lost entirely!
If it's just a two-hole lid like this, you're essentially done! Tie off the twill tape and trim your ends. If you're doing the whole side of a box, continue stitching in this manner until you have a neat row of horizontal stitches all the way down. The inside of the corner should have vertical stitches that lay nice and flat against the board.
And there you have it! Not perfect and pristine like a box fresh from your favorite vendor, but back in one piece, functional and ready for years of service in storing and protecting your collections.