But it is not complete...

Indeed, as far as bibliographical units go, this one is not complete. It would have been really nice if it still had the original binding, which would have given us valuable context for the gauffered edges. In its place we have an expert re-binding in rich brown calf with blindstamped floral ornaments front and back.
And it would have been really nice if the second volume stayed in touch. Did it have display same decoration along the edges? Was the inscription repeated on the second title page? Will it still turn up somewhere?
With the loss of the original binding more damage occurred: Our Pliny lacks two pages in the back. In the course of the rebinding (approx 1990) the last two pages were inserted as copies on paper similar to the original. This replacement covers fol 438 (last page of text, printed on recto only) and fol 439 (colophon only).
In the course of the recent rebinding, MS notes made on the old endpapers were preserved and they are inserted as copies. These notes are ascribed to Richard Heber (1773 - 1833), the English book-collector and bibliophile who amassed a library of over 150,000 volumes. In these MS notes Heber records his efforts to identify the edition and documents its rarity by a listing of more than 50 libraries or catalogues which do not record the title.
In spite of these imperfection, all the edges are here.