Kevin since you want the V-groove to be inset all the way around, draw a rectangle that represents the centerline of the groove on the top. then delete the top face leaving the rectangle. Draw the triangle for the V-groove at the midpoint of one side of the rectangle representing the centerline of the groove. Select all of the lines representing the centerline (Ctrl+Select) then get the Follow Me tool and click on that triangle. Heal the top face by tracing an outside edge and, if needed an inisde edge of the V-groove. You may need to select all of the top and run Intersect with Selected. Then delete the stuff you don't need.
I'll make some images to demonstrate.
Irony: The opposite of Wrinkly