'm guessing the magic numbers can be found by averaging the dimensions from all the bounding boxes.

Actually no. I tried that; but the average x-dimension comes out at 8.5882352941176470588235294117647; which was no good at all.

I'm afraid I cheated a little. The Y dimension was obvious as all the Ys come out as 12.

For the X, I inspected the data and guessed at 10, but that put to many extra spaces in:

C:\test>1114833
{
  1 => { 1 => "T", 4 => "S", 7 => "E", 9 => "C", 11 => "I", 14 => "E",
+ 16 => "N", 19 => "E", 21 => "O", 24 => "T", 26 => "Y", 29 => "U", 32
+ => "E" },
  3 => { 1 => " ", 4 => "I", 6 => "I", 7 => " ", 9 => "L", 11 => " ", 
+12 => "V", 14 => "E", 16 => " ", 17 => "V", 19 => "N", 21 => "U", 24 
+=> "Y", 26 => "Z", 29 => "L", 32 => " " },
  5 => { 1 => " ", 4 => "I", 6 => "O", 7 => " ", 9 => "L", 11 => "I", 
+14 => "E", 16 => "D", 19 => "P", 21 => " ", 22 => "B", 24 => "H", 26 
+=> "O", 29 => "S", 32 => " " },
  7 => { 1 => " ", 4 => "B", 6 => "I", 7 => " ", 9 => "C", 11 => "C", 
+14 => "Y", 16 => "D", 19 => "I", 21 => "T", 24 => "Z", 26 => "I", 29 
+=> " ", 32 => " " },
  9 => { 1 => " ", 4 => " ", 6 => "N", 7 => " ", 9 => " ", 11 => " ", 
+12 => "K", 14 => "A", 16 => " ", 19 => " ", 21 => " ", 24 => "L", 26 
+=> " ", 29 => " ", 32 => " " },
}
[download]

So then I tried 11 but it still put one extra in the middle row:

C:\test>1114833
{
  1 => { 1 => "T", 4 => "S", 6 => "E", 8 => "C", 10 => "I", 13 => "E",
+ 15 => "N", 17 => "E", 19 => "O", 22 => "T", 24 => "Y", 26 => "U", 29
+ => "E" },
  3 => { 1 => " ", 4 => "I", 6 => "I", 8 => "L", 10 => "V", 13 => "E",
+ 15 => "V", 17 => "N", 19 => "U", 22 => "Y", 24 => "Z", 26 => "L", 29
+ => " " },
  5 => { 1 => " ", 4 => "I", 6 => "O", 8 => "L", 10 => "I", 13 => "E",
+ 15 => "D", 17 => "P", 19 => " ", 20 => "B", 22 => "H", 24 => "O", 26
+ => "S", 29 => " " },
  7 => { 1 => " ", 4 => "B", 6 => "I", 8 => "C", 10 => "C", 13 => "Y",
+ 15 => "D", 17 => "I", 19 => "T", 22 => "Z", 24 => "I", 26 => " ", 29
+ => " " },
  9 => { 1 => " ", 4 => " ", 6 => "N", 8 => " ", 10 => "K", 13 => "A",
+ 15 => " ", 17 => " ", 19 => " ", 22 => "L", 24 => " ", 26 => " ", 29
+ => " " },
}
[download]

So then I tried 10.5 and voilą!

I also tried dividing the overall width of the longest line by the number of chars: 327-18 / 13 = 23.769...

And just now I tried taking the differences of all the x1s in the longest row:

T  18 15  28 27 0 
S  45 15  54 27 0 -> 27
E  70 15  77 27 0 -> 25
C  95 15 103 27 0 -> 25
I 119 15 128 27 0 -> 24
E 146 15 153 27 0 -> 27
N 168 15 179 27 0 -> 22
E 196 15 203 27 0 -> 28
O 218 15 229 27 0 -> 22
T 244 15 254 27 0 -> 26
Y 269 15 278 27 0 -> 25
U 295 15 305 27 0 -> 26
E 320 15 327 27 0 -> 25
[download]

Then averaging those: 27+ 25+ 25+ 24+ 27+ 22+ 28+ 22+ 26+ 25+ 26+ 25 = 302 / 12 = 25.166666666666666666666666666667

An' wadda ya know. It works perfectly!