Yes, the purāṇas themselves in the Nag Publishers reprints would be out of copyright, because they are photographic images of the Veṅkaṭeśvara Press editions. So the pagination and formatting and typesetting is that of the Veṅkaṭeśvara Press editions. The copyright pages of the Nag Publishers reprints say "[copyright symbol] Nag Publishers," but this can only really apply to the few added pages of front matter and the large added indices.