Harry, please remove any information that you feel gives away too much:
If you (and other participants seeing this) haven’t solved 10A yet, have you tried using frequency analysis? If so, what type of cipher do you already know matches the data? There is a bit of a twist on that cipher, and you should use the case file to help you find that twist. Once you find it, try using some cribs! They really helped our team in solving it.