The SCNOO should fit your Leica II if it was made after the introduction of the SCNOO without modification. There should be a slot at the bottom of the winding stem for the SCNOO drive shaft to bite into. It will only fit cameras up to and including the IIIb though, as the IIIc's body is slightly bigger.
Rick - In Tabulas Argenteas Refero
Loaded with film: Yashica 635
Latest Toys: Bell&Howell N-6A GSAP camera