i see that you have used pins to ensure the mould stays in 'register', if you use plasticine to mount your component in to make a two part mould. you can make as many mould dowels by indenting the platicine with a taperd pin or a pencil. when you have made the first half, remove the plasticine you will then have your pin holes there. pour the top half as before. its on you tube under '2 part silicon mold'. please forgive me if you already know about this.