Making pairs didn’t give anything that could make sense. I then wondered if morse reverse or swap would give a better range. Let’s convert the string to morse

..... ...-- -.... ..--- ----. ..... ..--- ----. ....- ---.. ...-- --... ..... --... ...-- ----- --... ..... ---.. ..... .---- ..... ...-- ..... .---- -.... ...-- -.... ...-- ----- -.... ....- ---.. ..... .---- ..... ...-- ----- ..... ----- --... ..--- ----. ..... ..--- ----. ..... .----

It didn’t take long by seeing this to spot the cipher. Notice the distribution of dots and dashes ? Groups by pairs of dots and dashes and count how many there are to get the decimal value

Now this is much better for Ascii range

83 67 87 54 54 82 69 83 84 82 65 73 78 84 84 87 57 57 87 74

Convert decimal to Ascii

SCW66RESTRAINTTW99WJ

Change the TW to 2

scw66restraint299wj

As usual, making pairs always help

91 71 71 91 70 71 40 40 81 80 32 81 51 41 41 01 42 40 80 60 70 91 81 40 12 40 31 81 40 12 40 31 81 71

Notice how the last numbers are always 0, 1 or 2?

Reverse the string

17 18 13 04 21 04 18 13 04 21 04 18 19 07 06 08 04 24 10 14 14 15 18 23 08 18 04 04 17 07 19 17 17 19

Looks like the range is between 00 and 25, convert numbers to letters (0=a)

RSNEVESNEVESTHGIEYKOOPSXISEERHTRRT

Reverse

TRRTHREESIXSPOOKYEIGHTSEVENSEVENSR

trr36spooky877sr

Make a 5×4 grid

Read left starting at the upper right T

tsr47perfection783qv