I should perhaps now compare Wittgenstein's treatment of Augustine's text with Mulhall's treatment of various texts, but I don't think I've got to a sufficiently clear or complete view of what Wittgenstein says about Augustine (if he says anything at all about him) to do that. So I'll press on with Wittgenstein instead.
The first paragraph of §2 begins with a reference to "that philosophical concept of meaning," which seems slightly ambiguous. Does the concept in question belong to the interlocutor who asks about the meaning of "five" in the shopkeeper example? Or to the narrator, who says that only the use of the word "five" was in question, not its meaning? Or do these two share an understanding of what "meaning" means? The matter seems to be cleared up in the next paragraph, which mentions Augustine again. Having said that the philosophical concept of meaning belongs in a primitive idea of how language functions, the narrator says that we could also say that it is the idea of a language more primitive than ours. Then he tells us to think of a language for which the description given by Augustine would be fitting. This is not quite the same as the shopkeeper story, and it is introduced in way that suggests the shopkeeper story was not intended to fit Augustine's description. After all, why invent a new example/story to do this job if we have just been given one?
The story we get now is of the builders A and B. The first thing we are told is what the language is for: A is building and B is his assistant. When A calls for a particular stone, B brings it to him. There are four kinds of stone, each with its own name. And this is the whole language, we are asked to imagine.
As with the shopkeeper, there is something strange about this story. Why are there only two people doing the building? Why isn't their work done more cooperatively? How heavy can the blocks be if B is carrying them single-handedly (is he Obelix?)? Both this building and the shopping in the previous section sound a lot like children's games. Whether that matters I don't know.
A second thing to note is that in the Augustinian picture, the meanings of words are supposed to be the objects for which they stand. But here the meaning of "slab" seems clearly not to be a kind of object. It means something more like "Bring me a slab!" Is Wittgenstein trying to show how embedded language/meaning is in activities or forms of life? Or is he getting his own interpretation of what Augustine says wrong? Even if he got it wrong deliberately, this would be weird, so I expect he's trying to make a point about purpose and practice in connection with language, but it's still too early to draw definite conclusions.