looked like it needed a 'spacer'.... Long and short of it it's in a box in my loft
the genuine one does need a spacer, IIRC the 2 bolts on the drivers side screw straight in, but the passenger side is raised to allow for the hand brake cable.
basically the spacer has an internal and external thread, that secure the hand brake, and then raises the height for the other side of the arm rest mount.
I had to get one for mine, as the bloke i got it from left his spacer on the car the arm rest came from, £1.50 odd from the stealer's.