Bought one from the Mercedes dealer many years ago for a W110 but haven't installed it yet. I would suspect that it would fit perfectly as it looks very good. Recently bought some aftermarket ones for a Ford off of Ebay, which the company also sold through their website, and I am not very satisfied as they are not formed exactly right. It is pretty much a crap shoot with aftermarket panels. My body guy says he only buys panels that have been certified for fit and finish, and approved for use by insurance companies. So look for any certifications. You can't go wrong with original OEM parts from the Mercedes dealer if you can get them and can afford them. But sometimes you have no choice and just have to get what is available and make it work.

What companies have you been looking at? Maybe others on the board can give you opinions on other parts they have bought from those companies which would give you an indication of their quality in general.