Who on earth is Marco?

Okay, I've sat through all 5 hours of Seagull Island and I'm completely baffled - Who the jimminy is Federico Tocci (who plays "Marco", as listed on imdb) - He was born in 1972 which would have made him about 7 or 8 when Seagull Island was shot. There is no 7 - 8 year old boy called Marco in the series... at all.

Answers on a postcard.