Welcome to the wonderful world of vintage sewing attachments! I warn you, this can become a very expensive addiction. :-)
Since some of you asked, I thought I’d write a little more about the hemstitcher. It is a wonderful, vintage attachment available for models 15, 66 (except 66-1), 99, 101, 127, 128, 201 and 221. Here’s the set for the 15 class and the 201:
The set consists of the attachment itself (note the huge hooked piercer),
and a special needle plate, an offset screwdriver and a special mushroom-shaped attachment screw:
There are five different needle plates available for the various models. Here’s the plate for the Featherweight (221K):
All of the machines that this attachment was designed for are straight-stitch only. The attachment pierces a large hole and then allows the machine to form a zigzag stitch to hold the hole open. For a nice hemstitch you would stitch down one side and then turn the work around and come down the other side. If you want a picot edge you stitch down one side only and then trim the fabric away up to the hole. It’s really very cool and beats the pants off the wing needle!
If you have one of these vintage machines and want to find an attachment that fits it, here is a list of the plates for each model:
Class 15 #121388
Class 66 #121389
Class 99 #121389
Class 101 #121390
Class 127 #121391 (needs screw #202)
Class 128 #121391 (needs screw #202)
Class 201 #121388
Class 221 #121392
Note that the set is always numbered #121387. The part number for the plate is on the underside and number #121388 for the 15 and 201 classes is the most readily available. The one for the 221 (probably because of the ever-increasing popularity of the Featherweight) seems to be the most sought after and therefore the most expensive.