The thing that the OP may run into with the "attached" part is that an AR7 breaks down into 4 components (maybe 5, depending how you count: Barrel, action, magazine, and stock ( the buttplate comes off, so that's the fifth part). The mag is in a separate hole in the stock from the action, but they're all stored in the stock.... so.... the mag is "attached" in that it's not in a separate location or container, bit it's not in the magazine well, either.
COmmon sense would say that this meets that "not attached" part....but we're talking gun laws, so common sense need not apply.