Trust me. If it isn't too bad, leave it. I had my front seat leather replaced on my brand new 1999 S420 because the beige leather came "pre-stained" from the factory. Every new S-Class on the lot with beige leather had the same stains. When I got the car back after having the passenger seat replaced, I was shocked and horrified how the leather looked. The dealer also said it will get better with wear. Then, I had the drivers seat leather replaced. It looked a little better, but did not look like the factory. I do believe that the leather will stretch out for you a bit with use.

The reason I say stop while you are ahead is that when they put the seat back together, I had scratches on the sill plate, the hose for the lumbar was not routed correctly and I could see it every time I got in the car. I have found that the more you take your car in for things, the more chance you have that something else will be mucked up. Now, I am talking from an appearance viewpoint, not mechanical. I am a bit anal with my car, and am very particular.

Good luck.