The crack could appear at any time, 1 year or 100 years or more after slicing & carving. I have had 100 year old ivory chips crack after I purchased them.

I believe that the red dye began to wear away after many years of play. If it was sanded, why not remove all of the red dye. It would be stupid to sand it to make it look old and then put new carving with new ink, without sanding again to make the print look old. You are assuming much too much, Rich.