Assuming this car has the original timing chain I can answer the question about maintenance history. The oil has been changed regularly.

If the oil is not changed as it should be, the microscopic grit wears the timing chain links and stretches the chain.

My 240D went 380,000 miles on the original engine and the chain still had no stretch at that mileage. When rebuilding the engine we replaced the chain for good measure.

Good luck,
Change oil hot and change oil often.