Richard, I hate to say but they are all one piece. A Ford special. They look the same as those fitted to the Duratec and may be other Ford engines. So I would try a scrap yard. On some engines they have a rubber socket srewed onto the top thread to mount the engine cover on.
Cheers
John.
Well thanks for update John and apologies for suggesting otherwise. I have noticed the unused studding seems a common feature with modern engines. I'm guessing on the models our engines are borrowed from his allows easy attachment of plastic covers to hide from those offended, the oily polluting engine
There are even bobbles on the end of similar studs on my Roadster suggesting such covers just clip on.
