PD p3120 question

So, I have recently got the p3120, however upon opening it, the twist mechanism seems to be made of black plastic and looks not very sturdy. Also the gap between top and bottom half of the body is uneven …maybe because of the way it had been stored or used by the previous owner. Can someone else who has this pencil share any description regarding the internals? Just want to If I bought the original and not a knock off.