Factory disc brake rotor question

Inside the rotor is for the stud head which, when the stud is pressed into the hub, holds the rotor to the hub. The swedge was a one time only, on the hub side to lock the rotor and hub together from Kelsey Hays. Not many can be found in this condition since the last OEMs were 1972. The studs are pressed out from the hub side. The marks on the inside are from the face of the stud head.