I'll have to look at mine when I get home. I picked up a 99 hand crank in a bentwood case, but never gave it a good look to see if it was different than the one on the 66 or the repo one.
to the OP - looks like the right knee bar. if it does not work, then something may be wrong with the controller under the metal cover, or the wiring. I've got a 128 in a case with that style knee control, and another 99 in the later style knee bar (has a slot instead of a barrel end and takes a different type cord)