Rabbi Nathan Marcus Adler here is holding a book which does not exist; *his* book, which definitely did exist, but (probably*) not in this form.
His commentary on Targum Onkelos, which he called Nesina Lager, is depicted in his hand.
This is the title page. He published it as part of a mikraos gedolos chumash which he called Toras Elohim (yes, that), and had it printed in Vilna by the Romm press, in 1874.
Now the reason why I asterisked "probably" is because it is *possible* that he personally had his own copy bound with that title on the spine.
But if not (and I think probably not) then this is what the artist put in, and must have therefore come through instruction.
In the 1620s Rabbi Joseph Solomon Delmedigo wrote:
"No teacher or father gives over the full content of their heart to their student or child, and because of this the truth suffers. But I swear: in my book Basemath I do not defer to anyone but Chazal and I do tell all unadorned.
If I am mistaken to do so, God is good and atones me."
Of course now you are wondering, what does he say in his Sefer Basemath. It sure would be nice to know, as ironically, we don't have it!
However, that does not mean that he never did write it. We have testimony that the manuscript did exist, by Moses Mendelssohn of all people, who writes that a famed bibliophile, Rabbi Shimshon of Slonim, had it.
In this page of milah registry, the brit milahs of a 56 year old man, and his 3 sons, aged 24, 20, and 17 are indicated.
What gives?
Almost 200 years after masses of Jews were forcibly converted to Catholicism in Spain and Portugal, some of the descendants of those people were still glad to get the heck out and join Jewry outside of the Iberian Peninsula.
The father here, the 56 year old, is Abraham - formerly known as Miguel - Lopez (1711-1775). He was one of three brothers, the son of a man named Diego Jose Lopez, who fled Portugal and moved to America.