I got some used 1970 Delta 88 rotors.
They look like they might be OK with just a light cut . Pads didn't have much wear
looked for a min dimension stamp on them, but can't find it. Internet is no help either. This rotor measured 1.254 inches.

 

From the 70 Service Manual.

 

There used to be a book that we would look at for minimum rotor or drum thickness at the shop I worked at. I think they are still out there on the net somewhere. Was the brand called Ammco? Cant remember....

 

The OEM rotors should have the min thickness number cast into them. In any case, Page 5-52 of the 1970 Chassis Service Manual.

 

Thanks Joe!
Looks like I'm OK for several more light cuts on tis one.

 

And as I've posted previously, when they are no longer serviceable, the 2003-2006 Cadillac CTS front rotors can be made to work. That's what I have on mine.

 

Sorry for posting the wrong information, Ive been slightly exhausted and still paying respects to a good “Olds” friend of mine!😁. Glad that Joe was able to get you on the right track!