The early US 380s had a single row timing chain that was at risk of premature failure. Other M116/7 engines have a more robust double row timing chain but the general thinking is that you're playing with fire beyond 150K miles on any M116/7 chain.
It's also hard to judge the mileage on a gray market car because I'm pretty sure MB didn't sell a car with LHD and MPH speedo anywhere but North America (The UK has RHD). So I'm pretty sure the km/h speedo in this car was replaced as part of federalizing the car. Who knows how many miles disappeared with the km/h speedo? What you want to see if mileage is a concern is how old it was when it entered the US. If it came in in 1985, how many miles could it have racked up in a year? If it came in in 1990, it could have had a heck of a lot of miles before federalization.
At this point, thought, all that matters is the condition.