I don't believe it's down to either a dysnumerate MoT tester or computer record, or a plate change. For two consecutive years it did 120, then 110, thousand miles.
The seats - all of them - have been jolly well sat in, more so in the back than the front left, so it has evidently been a taxi (almost certainly for the two high mileage years at least - over 2000 miles a week!) or corporate staff transport barge. I'd guess at an airport taxi.
They've ditched the overmats and the service history, I suspect; most dealers would mention the history if there was one. I wonder how much if any of the paint is original...
Even so, it's a tribute to Mercedes quality that it still looks so (relatively) good, or indeed that it's still running at all.