I've been looking to buy a set of used OEM rims and lug nuts for my 1990 560SEC. I understand the correct OEM rim size is 205/65-15. How do I ensure that the rims and lug nuts I buy are correct and authentic (i.e., size and offset are correct and they are not aftermarkets). Is there a stamp on them that I should be looking for (i.e. "Size: _, Offset: __, Mercedes Part # __ (or updated Mercedes Part #))? If not, is there some other way to ensure that I am purchasing correct and authentic used rims and lug nuts for this vehicle?