If your 74 seats are like my old 78 seats were....
I replaced the seat cushion with memory foam. Very easy and cheap. I just bought a memory foam pillow and cut it down. The seat leather cover just unclips from the frame if you take the seat out of the car.
The seat back is even easier. It's hollow. You can put your hand (arm actually) up from the base at the rear of the seat. I used to keep waterproof jackets up there out of the way. Also a good hiding place for satnav unit when parked overnight somewhere. I rammed a cushion up there when I wanted more back support.
Nick
