Next we have to calculate the width of the V carving at the ends — this could be done w/ some trigonometry, but it’s easily done by just drawing, so:

(the triangle is made by drawing a tall rectangle, rotating it 15 degrees, the positioning the rightmost tip at the bottom midpoint of a duplicate of the profile geometry and Boolean subtracting it, then flipping it along the vertical axis and repeating)

Similarly, we also need to know how deeply the 30 degree V endmill can cut — assuming a 1/4" diameter tool:

so we will want at least 4 passes — easiest to make them even, so duplicate the profile V and reduce to 0.25 scale:

then make 4 rectangles that height which are wider than the V and duplicate the V 4 times and drag each duplicate into registration and stack the rectangles and then do Boolean Intersection for each pair:

Next draw a rectangle as wide as each of the truncated cones which is as tall as the box (for the first):

aligning it vertically w/ the box inset and horizontally w/ the matching cone section — repeat for each:

EDIT: but note that the successive rectangles should have their height reduced by the diameter of the endmill (this is not shown)