My black box pleat leather drivers seat was extremely tired when I bought the car (1975 2200SC) and I had the following work undertaken:
1. Rear of seat completely restitched as it had come away and had been temporarily fixed with staples!!
2. New leather panel put in along right hand edge
3. Box pleat pattern re-shaped as it had become very flat over the years.
He also supplied a restoration kit which I duly used and my complete interior now looks 'as new'.
The work was carried out to an extremly high standard and I would reccommend him any time.
His name is Martin Dawson and he can be reached on 01944 758842 and he is based in Malton, North Yorkshire. I don't know how close this is to you.
That gives me something to think on. I am going to try a giving the seats a good going over with hide food ect., see what difference that makes then decide on more drastic measures!. I want my car mint!