How would you make this?

[PWD]

Hi guys,

I'm new to wings 3d but in the past I used polymodeling with 3dsmax and then surface modeling with rhino.
Since you have to do some "mechanical like" thing there are no problems, but you have to have a clear idea of what you want before you start.
With wings 3d I think that what you do, can be a start point for what you want to achieve because you see directly what you're doing.
So please, how would you make this?

   





The internal hole for the finger is 18mm in diameter and the stone is 5mm in diameter.

Do you think it's achievable?
Let me know, please.

Thanks
Marco