Found a NEW top AND bottom rad from separate vendors in Italy on www.subito.it Much cheaper than even a re-core! The first one was difficult as I 'no speaka da lingo' so had to Google Translate everything! The second guy was a joy to deal with as he spoke great English, although Poste Italiane is totally unreliable and slow (4 weeks!) Worth looking at that site (sort of Italian Gumtree) if you need parts.
those interested in values i paid £7750 for mine in January 2016 , 4000 miles,top condition, totally standard 1 owner from a dealer oop north. Theres a black and white one in Bennetts currnelty for £9499 with similar miles but its been there a while.
Bennetts offered me 4.5 for my Italia 800 and have one for sale with 4k miles more than mine for 7k so a fair old mark up . Great dealer though .