A personal rule about punctuation: A singular possessive word ending in s gets an 's even if the next word begins with s, even if the possessor is Biblical: Jesus's socks.
Otherwise, I would have punctuated this entry differently:
I have questions too. When the possessor is a book and therefore italicized, does the 's take italics as well? Yes, for visual consistency or no, because those last two characters are not part of the title? I say no, so that the apostrophe-s are not mistaken. Or, if the word is in quotation marks and also possessive, which takes precedent? If I wanted to refer to "Davies" or the punctuation thereof, should I write "Davies's" or "Davies"'s? I should rewrite the sentence.