Perhaps, but why didn't you buy a new MB fender from the start?

What year 190 ?

Unless a body part is CAPA , ICAR or some sort of German equivalent certified, it may be of lesser quality and the buyer must be willing to accept that. I've noticed that some parts are NSF certified but I'd be suspect of an organization called National Sanitation Foundation would have the background.

For really great body work, you need to send it to Arthur Tussik https://www.youtube.com/user/tussik01/videos?disable_polymer=1

There are some that say some of his heavy repairs are iffiy but they are worlds better than any hack in the US. Given the cost of cars in Eastern Europe and safety of a typical car there, this is an acceptable risk.