Picot hemstitcher cover plate numbers:
Class 15 machines take the 121388 plate, the attachment thumbscrew number is 51347A
Class 66 (EXCEPT the 66-1 or 66-3) take the 121389 plate.
Class 99 machines take plate number 121389
Class 101 machines take plate number 121390
Classes 127 and 128 takek 121391 (including screw number 202)
Class 221 takes plate number 121392.
They all take the same attachment thumb screw. The Singer part number for the hemstitcher itself is 121387.
This is according to the manual that came with my hemstitcher... My other hemstitcher is a "generic" for "Rotary machines"....wonder if that means I need to buy a White? LOL!