Our Garmin GPS thinks the entrance is on "Meda" avenue, but it is on "Aston" just west of the Meda and Aston intersection. Also, the swale at the entrance is quite deep and can be a real bone-jarring experience lest you slow down to a creep.
This year Casini has added camping cabins to their offerings. We stayed one night. The grounds crew was working on the road at the entrance, but the new dirt and road graders were not a problem. The one lady at the front desk (general store) was friendly and made sure we got a site that would fit our need. The area was quiet, the wife enjoyed the shops in town, we got a good night's sleep, and moved on.
The campground is now named "Windsor Wine Country RV" in Windsor, CA. The sites are quite close together, and the facility has a well-worn appearance to it. But -- if you are looking for an RV park in this area, you'll find few to choose from. Wine Country RV suited us quite well during our visit. The folks running the park are very nice and were eager to help us out at any time. We've stayed here before, and we'll probably stay here again when we're in the area. We paid by the week, and the rate was $214 / week. Previously, there was a water park associated with this park. The water park has closed, but the RV park remains.