A correction to the last post: I goofed (no excuse) on typing the model numbers for the two knee levers. My curved one has the same number as Janey's curved lever. The difference I found was that the mounting arrangement I have in my 128 case, which is near identical to her curved lever in the 99 case, is accommodating an almost straight lever.
It's challenging that cases, levers and other parts found with any machine can so easily be mismatched. And, for someone totally new to acquiring vintage sewing machines, it causes me to question whether it's even worth the effort to try to asssemble a machine as it was originally shipped.