I think you need to ignore delivery, VAT, road fund licence etc, you are only interested in the On The Road (OTR) price, in fact, you don’t really need to know that. What MB pay for the car is totally different, but MB don’t want you knowing what price they have agreed with the manufacturer.
All you need to confirm, is the Advanced Payment (AP) at time of order and the cost of the extras, fuel, wheels and camera, including VAT. If that is the amount you paid, then you owe nothing more.