Not sure I got this right. With case ref. you'll go crazy, too many. Pam+ref number to bypass the 3 digits block, example : Pam127 . Just too many of them imho.
I'd say go with cases common names, size and movements. Some are: Fiddy , Radiomir , 44mm , 47mm , Egiziano , 6497 , Submersible , etc...