The Logitech Lift mouse is in the little side. I did this using @Antonio's scan so my hand fits better. 

I have to make some adjustments, for example to make it fit tighter so if I take up the mouse it stays in place with the mouse. 

I uploaded the Blender file to make any adjustment. There is a kind of deformed cube with four modifiers. 

• To manipulate the actual shape, edit the cube and move vertices around, even add some.
• You can change the thickness of the jacket in the “solidify” modifier.
• The fitting to the mouse can be adjusted via the offset of the “shrinkwrap” modifier.

This is for the left handed version, but just mirror it and it will work for the right handed one.

Printed in TPU with supports.