My 1990 Plus 8 (3.9 injection) is fitted with (I think) an after market ITG foam air filter that is starting to deteriorate.Rather than replace it with a similar item, I would like to revert to the standard air cleaner which I believe is a cylinder with a trumpet intake. Can any one tell me whether this is a standard Morgan part or a Rover part please. I have looked on line for part numbers without success, there are one or two old Range Rover filters on ebay but I'm not convinced they are the correct items. Thank you.