L322 modifying seats and door cards from 2003 to 2012….

Hi all, really in need of some help and advice, I recently bought a new roof liner that was off a 2012 l322, when I arrived at the chaps place he had the car there with all the interior, after talking with the chap he said that the seats and door cards would simply just bolt into my car, so we did a deal and I cam away with the seats, after a week of cleaning the seats putting in new roof liner and removing the old interior I finally got around to putting the new interior in, I started with rear seats, they all went in well and easy, they the front seats, but when I put them in, the brackets are a different size to the mounting points on the car, has anyone done this or know how I can resolve this issue? Also the plugs and the front door cards are different, can these just be rewired if I get the plugs that fit?
I also had the steering wheel, that fits and all plus fit, but only function that seems to work is the heated steering wheel, the rear heated seats work fine as the plugs were the same, also rear windows and automatic locks work.
Would really appreciate any help you can give me on this
My Range Rover is a 2003 l322 td6 vogue se, the seats door cards and steering wheel were out of a 2012 l322 Westminster .