Rotor ID, possible replacements for OEM 81/82?

[retrex]

Hi all, I need help in identifying and in determining if a set of rotors that I have purchased are usable on an 82 CBX. The rotors in question in general look like 81/82 CBX ventilated rotors. They look to be in new condition. They have the same rotor diameter, center hub diameter, pad swept area, and bolt pattern of the standard CBX rotor. The back of the rotors states 9mm service limit, CBX rotors specify 13mm. The differences between the two are basically in the overall thickness of rotor, ventilation gap between rotor brake pad contact surfaces, and the thickness of the pad contact surfaces. The overall thickness of the purchased rotors is about .495 inches, this is in new condition mind you. Since I don't have a new CBX rotor to compare to, all I can say is the ventilation gap and the thickness of the pad contact surfaces are slightly less than CBX rotors. I am thinking that this is possibly an 83 GL1100 part, I'm not positive however. Can anyone ID this part? Also, what do you see as a possible problems with using these thinner rotors on an 82 CBX? Let me know what you think. Thanks