Cryptanalysis

How do we have to handle punctuation, digits and diacritics from the original message ? Delete, translate, ... I haven’t found "convention" about English numbers corresponding to AQT translation for German 8.
Thanks.

ENIGMA handles only 26 letters and nothing more. Numbers are kept as they are. Here the text is in english, no need to handle any diacritics.
My guess is that we can resolve this problem analiticaly and not with a statistic approach. the hint "FLAG" or "THE FLAG" at the end may be sufficient to do a brut force attack and find the good permutation of the plugboard.