One quick way of telling a Euro between a U.S. model are the bumpers. The U.S. versions have much larger bumpers than the Euro models.

Yes, make sure the timing chains, tensioner, guides and rails have been changed, or prepare spend $$$$ for replacement. If they (any of the mentioned) break, the engine is likely destroyed.

Also, know that window leaks from the rear window/trunk seals/taillight seals, etc., are also well known problems on these cars.

The 85' 500SEL also had standard driverside airbag. This may have also been the case with the 85' 500SEC, but it was optional on the other 85' Mercedes, except for the 300CD, 300D, 300TD and 380SL, all of which it was not available on. ABS was also standard on the 85' 500SEL.

I almost bought a 1985 500SEL. It was beautiful and had 152K miles. I just could not bring myself to pay $5500. for it. I ended up getting my 1985 380SE (same car with a smaller engine/shorter wheelbase) for $4500. less. Not as nice and it has its quirks, but is it good enough for what I want it for.

Good luck!