It has nothing to do with you or your integrity. It has to do with saving someone else's life who thinks that tires this old are safe to risk their life on in a high speed event on a track.
It has always been buyer beware.
Unfortunately it has always been an issue with the clock running on anything made of rubber. Some items will last longer then others.
Tires are not like gold bars where you can buy them as an investment and store them forever.
High performance tires in general even new have rubber compounds designed for high heat conditions. Low heat conditions as a result are on or over the limit for low temps. 20 f is about the limit for them before you have issues.
Some of the cracks in the rubber are superficial due to the action of Armor all on the rubber.
Multiple mountings of tires works against them as well.
Even new tires can fail just going out the driveway.
This is just something people should be aware of and make their own decisions on.
I have no vested interests in negatively effecting your sales. Best of luck with that.