I want to 'clone' an existing model kit I have (an articulated figure) into a more durable resin. The model kit I am using is rare and discontinued. What would be the best way to do this?

My plan now is to create a silicone mold of the model sprew, then use a durable resin to create a new sprew (hopefully) identical to the old one. The only thing I am worried about is cutting open the silicone mold, it seems very difficult to do correctly.

Does anyone have experience doing anything like this? Any advice?