Here's my approach.
The main surface is a network between the top ellipse and the four side profiles.
Then it's trimmed with the two side arcs to make the finger hole.
The edges are blended together using the 3 small arcs as profiles to ensure continuity. Notice that in order to draw these 3 arcs I used 3 pairs of lines perpendicular to the side edges and then I blended them with G2 continuity.

The file contains all the curves used as well as the final shape.
Cheers
Dan