This Singer UK page lists all of the Singer cams, their part numbers, and stitch pattern name.
You might want to grab a copy of that in case that web site doesn't last forever. Lists the flat discs, black top hats, white flexi-stitch top hats, flat flexi-stitch 2-pattern, "Black Top Hat Flexi-Stitch with gold print & grooved backs", and "White Flat Fashion Disc and Flexi-Stitch two patterns, reversible."
http://www.singersewinginfo.co.uk/pattern_cam_list/