My ’92 400E came from Canada, in Toronto. You should check with the DOT. It is probably a good idea to talk with a dealer that does a lot of these. As far as I can tell about all they did to mine was to put a US spec speedometer and match the odometer recorded mileage. I bought mine from a US dealer in Rochester, who, in turn, bought it at auction in Toronto.
One note: check *closely* for corrosion. Mine was okay but the exhaust system was shot
'00 ML320 "Casper"
'92 400E "Stella"