Mines started leaking.
It's a 2.5 petrol.
Are the twin lipped versions the ones to go for?
https://www.ebay.co.uk/itm/LAND-ROV...818559?hash=item5b3aff113f:g:qIEAAOSwIdpZ22DL

Either will work, just get a good one. Should last another 30 years or 100,000.

Twin lip version relies on the contact surface of the crank, where the new second lip sits, being absolutely perfectly clean and rust free - any dirt or rust on the contact surface of the crank and the second lip will be shredded.