Any Mercedes prior to U.S. model year 1981 would have a vin number starting with the chassis number. If your vin is indeed starting wiht a 126 then it is a grey market car. The W126 chassis was introduced to Germany in 1979 as a 1980 model. InGermany there model year starts in the Summer. Also, I have a full line broucher for Mercede from 1980, and there was no U.S. model 380. There was the 280 and the 450.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section