I just picked up some Giles Berthoud fenders earlier this week. I have them installed on my '73 Italvega Nouvo Record which is set up as a fixed conversion and is also my daily commuter. I am pretty sure these fenders will stay with this frame. So, my question is whether or not it is a bad idea to drill and tap a hole in the <edit>chainstay bridge</edit> behind the bottom bracket to attach the rear fender more securely than it is. Currently I am using zip ties for lack of anything better. Normally I would be against permanently altering a frame, but I don't believe this to be a huge collector's item. Also this procedure would not limit any future functionality of the frame.
Has anyone here done this?