Based on its appearance, the car you are referring to seems to be a first-generation Mini with the Tritec engine, which is considered to be of high quality.
The components might potentially consist of:
Timing chain guide.
The timing chain cover has integrated webbing designed to secure the chain onto the bottom sprocket. The chain became detached when it became slack.
What is the issue with the washer?
This automobile previously had a malfunctioning chain.
If the current situation is satisfactory, then you should be in a state of being acceptable or satisfactory.
If not, at least in the UK, there is a large number of first-generation Minis being dismantled, making it inexpensive and simple to get a new engine.