Sorry for the confusion, Yes, VM is the Mikuni round slide type of carb. Good all around carb. The CV refers to the constant velocity Kehin? fitted as stock to Harleys for years and referred to in a previous post.
By their nature, (variable venturi) the CV's are a very flexible carb and could be made to work on the 61" knuck. Don't have the experience myself, although I did use SU's extensively in my youth, when my right knee would bend around them.
The CV 40 is just an evolutionary refinement of the old SU.