Not to worry. I finally found some of our relatives in a village about 30km up in the mountains from Nice yet they considered themselves from Nice. Just means a lot of patient searching.
I got suspicious when I saw Eulalie's and her brother's birth registrations in Saint-Dominique's but no marriage for either of them anywhere in the town of Nice - especially when marriages usually take place in the bride's parish. I think the Gautier's may have moved out of Nice but I too think they would have stayed in the area. With Horace being a locksmith I would expect them to be in a fairly well populated place.
Like I said, they're out there somewhere - lol.