I have a partial explanation, and an imperfect (but good enough) decryption method.
Building on the excellent work by GentlePurpleRain, I noticed a pattern, which is much more apparent if we apply a small modification to his setup.
First of all, arrange the 40 symbols by columns instead, like this:
AEIMQUY37@
BFJNRVZ48$
CGKOSW159#
DHLPTX260%
With this setup, the text looks like this:
6TM6+XSYX#+MW+2WV+5#4UT+%9
88UW+FI+PXQT+$U8#97+ZWN+6T
M6+XSYX#+MW|RSMXYFMVXWMH+9
UXX+8U$U4+SMUZ+8U#56+18Q4+
BC@H37F5+NWZ+MP2+$Q2@U+JS+
A+D1E2#B%+MW+AFN@JK@DQ+23D
Y03B+XS+12Q+EZEMPEFMPMX3|M
VW+9ZZY$#+PX1O+OAPPHAIAJP+
LVI+Y$#D63B+1QP+9M4Y+6RUS|
As already established, + signs are spaces, and |
are periods. Now, look at OAPPHAIAJP
, which is the word that GentlePurpleRain already identified with SETTLEMENT
.
If you look at the alphabet table, you will notice that the encryption is a simple shift to the right.
With this hindsight, I tried to decrypt the first sentence, and I managed to get this:
6TM6+XSYX#+MW+2WV+5#4UT+%988UW+FI+PXQT+$U8#97+ZWN+6TM6+XSYX#+MW|
that+hcihw+is+ton+owned+cannot+be+dleh+ransom+rof+that+hcihw+is|
Which, considering the reversed words, becomes obviously
That which is not owned cannot be held ransom for that which is.
Only problem is,
I had to try different shift values for each word, and I didn't find any particular rule. In case anyone is wondering, for that line the shift where: -3, -4, -1, -2, -4, -5, -1, -3, -5, -2 (negative means to the left).
I'll try and come up with a more precise rule.
EDIT
As pointed out by f'' in the comments, the shift values are defined by the word's length (minus one, depending how you count).
I also have the full text:
that+hcihw+is+ton+owned+ca
nnot+be+dleh+ransom+rof+th
at+hcihw+is|noitubirtsid+w
ill+reven+gain+rewop+over+
noitaerc+for+eht+value+fo+
A+tcudorp+is+inversely+det
aler+to+sti+availability|e
no+offers+dlog+settlement+
dna+another+sih+warm+tfig|
or better:
That which is not owned cannot be held ransom for that which is. Distribution will never gain power over creation for the value of a product is inversely related to its availability. One offers cold settlement and another his warm gift.