The words that had <au> in Latin that have come into Spanish, Italian,
etc., through "natural" historical processes have simply been respelled
to match their contemporary pronunciation (e.g. Spanish and Italian
*oro* 'gold', from Latin *aurum*).
Gah! Of course. I had spent the weekend in Venice and been to the "quarter"
(i. e. "sixth") called Sestier de San Polo, which would be Sestiere di San
Paolo in Standard Italian. I only thought of this one example.