Strange, the nicks. Sounds like maybe the pads are gone and the backing plate is on the rotor, but the backing plates are usually softer steel or copper/bronze than the rotor. Those are some pretty hard steel.

2005 Model . Two Fast Eddy stickers , a bell and a clock . She's Lola . She tinkles and keeps time . http://s649.photobucket.com/albums/uu211/britbike05/