The last bit is a bit puzzling, to me at least. IIRC from Neil Millers postings, shell Cordovan leather is leather from two small areas on a horse's rump that was processed a specific way in Cordoba Spain. That method of tanning was brought to the Cordoba region of Spain by the Moors. That particular tanning process is what makes it shell Cordovan leather. If it is processed differently is it then really shell Cordovan?
Bob