Montalbano finished and I came back to that south east corner. I can't make an anagram out of the letters for 25ac. Originally I thought the answer might be aviator, but it can't be.
I can't make a sensible word out of 19d. I have I?T???K. I'm really not sure about that K, so have I got 26ac wrong? Are my letters right?
I think I got badly stuck on the last Vlad I did. There are lots of clues I can't fully parse and new words. I'm giving up for the night.