For what it's worth, Looks like the front DMC-12 rotors are from a Jag Sovereign series 1,2 and 3, 1968 - 82 rears. Also on the Double Six 82-86 rear. My orig DMC rotors hand measured: 254 mm dia, 24 mm height, 12.5 mm thich, 70 mm dia center hole, 4 bolt The Jags show: 262 mm dia, 25.5 mm height, 12.5 mm thick, 70 mm dia center hole, 4 bolt Specs came from www.dba.com.au Their #75 rotor. Probably close enough. No spec on bolt hole diameter or spacing. Jim 6147