Seats look great!
I know what you mean about it being tough.
My hands hurt for a day or two afterwards.
That front clip can be a bear.
Keep an eye on it for a while, yet.
If it does not hold firm after some time, take the back clip off and bend out those tiny teeth tabs that hold the clip.
You want the seat bottom to stay on tight.
When cutting for the seat controls, start way smaller than you think you need and work up slowly from there.
Less is more, here.
Take a can of Scrubbing Bubbles foam bathroom cleaner and spray the head rests and arm rests to clean them and knock down that shine.
After applying the spray foam, lightly hit them with a brush.
Clean seat leather does not shine, contrary to popular belief.
Great job!