Hello Marge,
Since I am part of a five-generation Napa Valley I think I might be able to help with your request.

A unique experience: http://www.castellodiamorosa.com/

The best chardonnay: www.rombauer.com/‎

Francis Ford Coppola’s Winery: www.inglenook.com/‎
Francis has finally been able to put the former exquisite Inglenook Winery back to its original grandeur. I had the privilege of working for Francis until I retired. Be sure to taste the Cask Cab and the Pennino Zin. Both wines are to die for.

My cousin’s winery: www.caymus.com/‎
You will have to phone and make an appointment to taste.

Fun and good wine: www.plumpjackwinery.com/‎

I am not familiar with Hewitt. It seems that wineries change names often in the Valley. These are the wineries I take visitors. Hope it helps. I just realized I will be in the New England area will you are in the Napa Valley. Enjoy your trip.