This lens collar *almost* fits the neck of the stereo zoom scope. You'll need to add a piece of foam tape to the inside to get a snug fit. I used some standard white double-sided foam tape, the kind you'd find at an office supply store.
My favorite setup is to mount the scope on a pan/tilt video tripod head with a very long mounting plate. The long plate makes for a great focus control, especially if you add some thick grease to make the sliding motion stickier.