The hole for the bolt that holds the rear brake on the frame is drilled top-down and I found out the reason reading a post on this forum. The frame is designed for Mafac brakes and the same bolt holds the fenders also. What could I do to use a new pair of brakes? I don't want to drill the frame. I thought about using disc rear brakes but the frame is old enough and it has no mount points for disc brakes. Any advice could be very helpful.