On his return to Milan, he soon became one of the most sought-after restorers of the day, a consultant to the Louvre and the British Museum as well as the leading collectors and connoisseurs in Milan and Europe as a whole.
Da han vendte tilbage til Milano, han blev snart en af tidens mest eftertragtede konservatorer, konsulent for Louvre og British Museum samt de førende samlere og kendere i Milano og Europa som helhed.