When Hagrid & harry 1st step into the market (Diagon alley) to pickup supplies before going to Hogwarts, there are some women talking then the shot changes& you see a couple walking by in the background. The man has gray side-burns, a red jacket (I believe its red or orange?), &a top hat.
I believe the man in the hat in none other than Christoper Moltisanti (aka Michael Imperiolli) with some simple makeup& prosthetics to make him appear slightly older?
I've searched every comination of Harry Potter&his name that I can think of but can't find anything to say that I'm not bat-sh*t crazy or if it's just one of thoe wierd uncredited extra deals he did as a favor for a friend or while simply visiting the set..