86-87 = 300D or 300TD, OM603, no gills
90-93 = 300D 2.5, OM602, has the gills
95 = E300D, OM606, has the gills

Interesting that the 96-99 W210s, both NA and Turbo, with OM606 engines, have no fender gills, the intake was moved behind the front grille beside the radiator.

Just curious, how many cylinders does the engine have? That will be a good indicator of what year the engine was. It's pretty easy for a chop shop to change things like front fenders and deck lid, but not so much the engine and drive line.

In any case I would run like hell. There are still way too many clean examples of the W124 or W210 Diesels available to mess with something like this.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech