I think the only (grammatical) passive in there could be "the book was misbegotten", if it were the passive of active "Russo misbegot the book" (with Russo bein

I think the only (grammatical) passive in there could be "the book was misbegotten", if it were the passive of active "Russo misbegot the book" (with Russo being the only possible subject, as you convincingly argue). However, the verb "misbeget" doesn't seem to exist anymore [1] - what remains is the old participle as an adjective, and as such the fragment is just a good old active sentence, like "the car was red". But we're now sort of off-topic, methinks. [1] Etymology Online: "bastard, illegitimate, unlawfully or irregularly begotten," 1550s, past-participle adjective from obsolete misbeget "beget wrongly or unlawfully" (c. 1300), from mis- (1) "badly, wrongly" + beget