Hi, 4acker is right, the Anniversary model has a special sump and takes more oil.
My Anniversary (1995) car handbook states 5.8 litres and it takes that amount.
if it is of interest to anyone I have two problems...
1) I have trouble seeing the fresh oil level on the circular end of the dipstick
2) when pushing the dipstick in I think it pushes the oil up the narrow dipstick hole and gives a false reading with oil spread up the dipstick
So I fill 5.5 litre and leave for an hour. This allows the oil to settle as a level on the dipstick. Pulling the dipstick smartly out a distinct oil level ring is just about discernable holding the stick horizontally in a good light
If there is no sign of oil I add 50cc, leave for an hour, recheck and repeat until I have the correct level.
Caution, from an oil level at the bottom of the dipstick to the correct level does not take very much oil.
This is my car, of course, and yours may act differently. It's a chore but I don't overfill.
Sorry if this is an egg sucking moment
