The authors greatly appreciate the assistance of Mr. Charasaiya in donating the specimens for this examination as well as the open discussions that have taken place that have provided further useful information on the process being used. However it should be emphasized at the outset that the details of his process remain proprietary to Mr. Charasaiya and any description of it here results from the conversations we have had with him - the authors have not witnessed the actual treatment taking place and nor do they have details on such important areas as the manner in which the diffusion materials are applied, the temperatures or timescales used.