For the capitalization, I'd leave it as is. This looks like what we would punctuate in Spanish as "¡O sage!, ¿what are we to do?", which is of course different from "¡O sage! ¿What are we to do?" (not different in meaning, just in style). The fact that you cannot make that distinction now doesn't mean you should eliminate it from the past
For the diacritic, I'd vote for consistency. Pick the most frequent one and use it (unless the difference could be intentional).