Note that we are way beyond anything taught in typical grammar textbooks. At this point in their work, you might want to push students to identify all of these as passive verbs, or, if you want to take the time, you can have them discuss which they think should be explained as predicate adjectives. I have made that distinction here, and given my reasons. Note that passive voice itself is the focus of KISS Level 5.7 - Passive Voice and Retained Complements.

1. The stately residence {of Monseigneur} was altogether blighted (PA) and deserted (PA). |

The sentence describes the condition of the residence rather than the act that caused that condition.

     [Adj. to "knowledge" that I possessed]. |

The sentence describes the lasting condition of the others, rather than the act of compromising.

     saw a sudden doubt (DO) {in them}. |

This is clearly passive voice because the focus is on the action, not the result.

Not only is the focus on the condition, but the participle "dilated" is joined to a clear adjective by the "and."

Here again the focus is on the action, so "were opened" is probably best explained as a passive verb.

Out of context, this could be taken as a passive, but it is more likely a description of the status of the faces.

The is a description of what is covered, and not a focus on how it they became so.

      to "trampled" as if there ^[#3] had been a struggle (PN) ]. |

The past tense implies that the condition, not the action, is what is important.

     the worse}. |

The focus is clearly on the changed condition of France, and not on how or what changed it.

     {of the old Sunday night} [Adj. to "night" when they had looked {at the

       lightning} {from the same place}]. |

This one could go either way, but the context suggests that the hot, wild night is instrumental in the reminding, so although I would not count the predicate adjective option wrong, I personally see it as a passive verb.