My '54 2.0 tdci originally had a cover which was missing when I bought the car from our local Ford Dealer. They agreed there had been one due to the used fittings and said they would take one from another carif theygot one in.
It seems that not all engines had them. Depends on the date but, like you, I felt it looked better. Some sound deadening also.
Needless to say, the dealer, being a Ford dealer, I waited, chased and hectored them to no avail. In the end I paid for a new one. Having had a lot of other issues sorted by them and so as not to lose goodwill I paid cost. About £30.
I looked on ebay and breakers yards and found many and various covers for any engine but mine. They are very hard to find used in my experience and thought a new one would do for me. I shall make sure that when it goes in for service or whatever I remove my cover so it doesn't get'lost'.
I didn't have one on my 2004 1.6TDCi, so I enquired at Ford about getting one.
The cover was about £40, and it also needed two metal supports to be fitted, and also 2 nuts. Total cost was about £60. I'll have a dig around and see if I can find the part numbers.