Seat restoration result
 

Restored my '84 seats after 10 years in the attic, before after pics: https://imgur.com/a/zpOZVWY

I used stuff from Colourlock. They matched the color from a piece of leather for the paint and for 'leather filler' which I used to fill up the holes and tear. Although I started with gluing pieces of leather behind the two holes. After that l painted it all and then used lots and lots of oil and topped it off with some protective layers. Originally the leather was stiff and felt like paper. It's pretty good now.

Wow.. Those are pretty significant improvements. What was your total expense for restoring those parts?

Probably around 100 euro.

That's some nice work. I would have thought those seats were too far gone to do anything with. Congrats on a nice project.