Let's see if by working together we can solve the initial part, at least.
AWVLI QIQVT QOSQO ELGCV IIQWD LCUQE EOENN WWOAO
LTDNU QTGAW TSMDO QTLAO QSDCH PQQIQ DQQTQ OOTUD
BNIQH BHHTD UTEET FDUEA UMORE SQEQE MLTME TIREC
LICAI QATUN QRALT ENEIN RKG
Looking at the
index of coincidence (the value of
kappa) for the above sequence --
[Duo2 GCHQ]$ kappa part_1.txt
0.062937
[Duo2 GCHQ]$
Kappa is approximately 0.065 for the English language, whereas it is approximately 0.038 for a purely random 'alphabet soup'. So we are clearly dealing with an enciphered English text.
Now looking at the observed value of
phi for the above sequence and comparing it with the theoretical value (a) if it was a polyalphabetic cipher and (b) if it was a monoalphabetic cipher, we see --
[Duo2 GCHQ]$ phi part_1.txt
expected phi sub r 781 (poly)
observed phi 1278
expected phi sub p 1353 (mono)
[Duo2 GCHQ]$
This result strongly hints that we are dealing with a monoalphabetic cipher.
The character frequency counts --
[Duo2 GCHQ]$ chaf part_1.txt
A = 00008 5.59% B = 00002 1.40%
C = 00005 3.50% D = 00008 5.59%
E = 00014 9.79% F = 00001 0.70%
G = 00003 2.10% H = 00004 2.80%
I = 00010 6.99% J = 00000 0.00%
K = 00001 0.70% L = 00008 5.59%
M = 00004 2.80% N = 00007 4.90%
O = 00010 6.99% P = 00001 0.70%
Q = 00020 13.99% R = 00004 2.80%
S = 00004 2.80% T = 00014 9.79%
U = 00007 4.90% V = 00003 2.10%
W = 00005 3.50% X = 00000 0.00%
Y = 00000 0.00% Z = 00000 0.00%
Total alphabetic characters = 143
[Duo2 GCHQ]$
The bigram frequency counts --
[Duo2 GCHQ]$ bif part_1.txt
AI = 00001 0.70% AL = 00001 0.70% AO = 00002 1.41%
AT = 00001 0.70% AU = 00001 0.70% AW = 00002 1.41%
BH = 00001 0.70% BN = 00001 0.70% CA = 00001 0.70%
CH = 00001 0.70% CL = 00001 0.70% CU = 00001 0.70%
CV = 00001 0.70% DB = 00001 0.70% DC = 00001 0.70%
DL = 00001 0.70% DN = 00001 0.70% DO = 00001 0.70%
DQ = 00001 0.70% DU = 00002 1.41% EA = 00001 0.70%
EC = 00001 0.70% EE = 00002 1.41% EI = 00001 0.70%
EL = 00001 0.70% EM = 00001 0.70% EN = 00002 1.41%
EO = 00001 0.70% EQ = 00001 0.70% ES = 00001 0.70%
ET = 00002 1.41% FD = 00001 0.70% GA = 00001 0.70%
GC = 00001 0.70% HB = 00001 0.70% HH = 00001 0.70%
HP = 00001 0.70% HT = 00001 0.70% IC = 00001 0.70%
II = 00001 0.70% IN = 00001 0.70% IQ = 00006 4.23%
IR = 00001 0.70% KG = 00001 0.70% LA = 00001 0.70%
LC = 00001 0.70% LG = 00001 0.70% LI = 00002 1.41%
LT = 00003 2.11% MD = 00001 0.70% ME = 00001 0.70%
ML = 00001 0.70% MO = 00001 0.70% NE = 00001 0.70%
NI = 00001 0.70% NN = 00001 0.70% NQ = 00001 0.70%
NR = 00001 0.70% NU = 00001 0.70% NW = 00001 0.70%
OA = 00001 0.70% OE = 00002 1.41% OL = 00001 0.70%
OO = 00001 0.70% OQ = 00002 1.41% OR = 00001 0.70%
OS = 00001 0.70% OT = 00001 0.70% PQ = 00001 0.70%
QA = 00001 0.70% QD = 00001 0.70% QE = 00003 2.11%
QH = 00001 0.70% QI = 00002 1.41% QO = 00003 2.11%
QQ = 00002 1.41% QR = 00001 0.70% QS = 00001 0.70%
QT = 00003 2.11% QV = 00001 0.70% QW = 00001 0.70%
RA = 00001 0.70% RE = 00002 1.41% RK = 00001 0.70%
SD = 00001 0.70% SM = 00001 0.70% SQ = 00002 1.41%
TD = 00002 1.41% TE = 00002 1.41% TF = 00001 0.70%
TG = 00001 0.70% TI = 00001 0.70% TL = 00001 0.70%
TM = 00001 0.70% TQ = 00002 1.41% TS = 00001 0.70%
TU = 00002 1.41% UD = 00001 0.70% UE = 00001 0.70%
UM = 00001 0.70% UN = 00001 0.70% UQ = 00002 1.41%
UT = 00001 0.70% VI = 00001 0.70% VL = 00001 0.70%
VT = 00001 0.70% WD = 00001 0.70% WO = 00001 0.70%
WT = 00001 0.70% WV = 00001 0.70% WW = 00001 0.70%
Total alphabetic bigrams = 142
[Duo2 GCHQ]$
A quick and crude automagical attempt at decipherment yields --
[Duo2 GCHQ]$ demono part_1.txt
icyso eoeya engen tsphy ooecr shdet tntll ccnin
sarld eapic agmrn easin egrhu keeoe reeae nnadr
wloeu wuuar datta brdti dmnft getet msamt aofth
sohio eiadl efisa tltol fvp
swap>
tr "[A-Z]" "iwhrtbpuoxvsmlnkefgadycjqz" < part_1.txt
[Duo2 GCHQ]$
Hmm . . . I see no semblance of any English text, above. Perhaps there is a degree of transposition involved.