'I' think the base is right, however, it's also possible Cristallerie de Sevres made their bases in a similar way. Most of my French vases have a large polished pontil mark. And I am no expert lol, I've only seen what I've seen online and on my own pieces.
I also think your vase looks right, because of the way the spatter is done, and I can't explain that but there's something different about the Sevres vases to the Leveille pieces I think. But if I were you, I would need more than my instinct to go on

The shape match would be good if it were to a near signed piece, finding a match to the spatter, or near enough would be good, and I do think you might find something very similar to the enamelling and maybe differences in the way the Sevres pieces were enamelled maybe.
Love the shape and the vase.
m