https://youtu.be/y3X1HWTT8BU

Learned lots with this car.
Many hours spent away from family when I could be supporting my kids and building cherished memories of quality time using a car which works.

Anyway in no more than 1200 miles I have done:
Suspension arms, airbags, sensors
Many loom repairs
Brake lines
Welded rear arch, rear sills and door frames.
New gearbox + transfer + fluid
New battery
Engine oil change
Rocker cover gaskets
Plugs
Water pump
Headlights and tail lights
Er, the list goes on and on.
Anyway can you advise me on options to repair this......Please listen to the link above - it sounds like a diesel now (I guess soon after I changed the engine oil).

You sure that's not the chain rattling? Video sounds weird, Maybe too close, but it's sounds very similar to an M62 Chain issue.

The chain tensioners disintegrate over time. Be wary of running it, until you know.

They are usually very quiet, but if the chain jumps, you'll have a much bigger problem!

That actually sounds more like chain rattle due to failed guides