i just purchased a 2004 E500 w/ 150k miles, and the front seats appear to have shrunk

I thought the box under the seats had moved, but they are riveted in pace with 2 rivets under the seat and 3 more in the box

Question: Any idea on how to fix this?

drivers side


Passenger side shrank more than the driver side

 

Pictures taken at different angles, what might be misleading, but looks like different models of seats.
Likely on 12 years old car driver seat was replaced.
When I still admire leatherette on 30 years old Mercedes, each time I see leather on 12 + yo, I usually cry.
Cars are still holding nicely, but leather makes it looking like old beater.