front brake rotor thickness

[87squarebody]

When measuring the rotors you measure thickness but what if the rotors have been cut?How can you tell what you have?I ordered a set of cpp modular spindels for my 87 and told vendor I had 1" thick rotors and got a call back that they woudn't work because the spindle is for 1.25" rotors only.What would I have to change to make these spindels work.Can I just change the rotors and bearings and use my calipers,pads,and all the other things along with it.