We are signed up for a Rick Steves' recommended Mondo Shared Tour of Naples on May 1. Had to change the date due to the closure of museums on May 1, but the Mondo Tours are still available. Hope this advice helps others, and we get enough people to fill our 3 hour walking tour of Naples. Should be an especially good day to have local help, if there are the typical local events and disruptions of a national holiday.
Molly