Oh poo is a term you might want to consider
That odd looking thing is actually a type of pop rivet which blocks off the oil gallery drilling.
I've replaced engines because of a leak there! Although the rivet costs around 58p i know no one with a rivet gun which will accept ¼ or so stalks on the rivet. It is possible to drill the block there and thread it and fit a bung, but thats not something a ford dealer would be allowed to do as a warranty repair.
Have a word with some local engine refurb places, they might have the facility to install a new rivet for you.
Your not having much look with the old duratorq's are you
