Not sure how my car compares, but my 95TDi Right hand drive (Australia) Disco has a slight lean to the right. Always has, even with all new springs a year or two ago. A few mechanics have commented on it at rego inspections but always let it pass. My landrover mechanic has checked it out and said there is nothing obviously wrong, and it is common for Land rovers to have a slight lean. One day I will have alook at the body spacers and see if that is where the problem is - but until then i am happy with a lean!

Not sure if this helps your question though....

 

You could have put the front spring in wrong, they are usually marked as to which one goes on which side.
You can also install a spacer to level it out, quick and easy.
Mike

 

Could a broken spring be causing the knocking feel?

 

Yes!
Mike