This one will be a bit easier than most, because it has been made known to you that this message is a telegram. Therefore, the plaintext ends with "end of message." Also, it probably contains at least one copy of the word-pair "full stop", which serves as a period or end-of-sentence marker.
WARNING: This cryptogram contains at least one "fixed point". These are letters of plaintext that encrypt to themselves as ciphertext. (For example, J encrypts as J, or something like that.)
A joint project of Brendan Bard, Prof. Gregory Bard, and Prof. Seth Dutter, University of Wisconsin---Stout (January 30th, 2019)