Originally Posted by
Grannyh67
OK, I love the 1921 Singer Red Eye, I have one that looks almost like that. The serial # is G4764462, do you think it is the same. I don't know if it is a 66 or a 66-1. Thanks
The 66-1 is a backclamp treadle machine. The 66-3 is a backclamp handcrank machine. That's the only difference between the two.
ETA: Your machine has been altered...the originals had backclamping attachments...your presser bar has been changed out to take side clamping attachments.