I took apart my 429's tension assembly, and Miriam, that Singer general-purpose refurbishing manual was simply invaluable!
Things appeared to be in the correct order, etc; however, I suspect that because there was quite a bit of gunk in there, parts were not moving independently as they ought to. For example, I would rotate the numbered dial, and everything else would rotate with it. As well, the spring, though it appeared to be in the correct place, was not 'springing' and 'returning', as you described, M.
Amelia, I am going to post photo/s to show you exactly the order in which things came off. I went a little further than you did and I also removed the long screw called the 'tension stud'. Be careful when you do this and note -exactly- which order the spring, washer, tension stud, and tension release pin come off in.
Amelia, by your photos, you have the notchy-edged dish facing the wrong way. See my photos and see also the Singer page here which Miriam sent:
http://www.tfsr.org/pub/technical_in...echanism_2.pdf
Although perhaps somehow I am incorrect on this? Miriam, do you have a comment as to which of our photos are correct; Amelia's notchy-edged washer dish facing dish out, dome in, or mine, facing dome out, dish in?
Photos to follow.
-C.