Is the car being offered by a private seller or a dealer. ( Or even a person calling themselves an enthusiast but is really a dealer )

One way to partially vet a seller. Run their phone number / e mail on google and see if other ads pop up. Ask if the title is in their name and look at title to see when it was issued.

Does your guy know cars to a deep level or is just unfamiliar with the details of a MB?

I'm not bought off by clean repaint / chrome / interior as these can be applied to any car to make it look good. I look at bolts to see if they are all the same type on an assembly , brackets and wire looms are in place , under dash looks as built , under seats looks good , under car and so on. In other words, look at places where the average person isn't going to look.