Hey!
Having recently finished the book, I've been following this thread for a couple of days - now it's officially time to stop lurking
I find this puzzle incredibly interesting and have been playing around with a couple of theories (more on that in another post later).
More importantly, I've seen something like this code before here: http://fabiensanglard.net/Ghost_in_the_Wires/index.php
Edit: See Chapter 27 for a prime example.
That is, by the way, also a very good book!
Anyway, here's my two cents: I reckon Mitnick's codes provide some good prompts for common types of ciphers (mandatory reading really).
Two other things of note are:
Mr. T gauges his intelligence with mathematical problems (such as Fabrisan's Conundrum, which he solved)
We know from the mention of a logarithmic scale (btw the pattern is written in a rotation; circles and the natural logarithm are intimately related i.e. Euler's identity) that their mathematics should be compatible with our type of mathematics
I think that Mr. T would have followed a rational and pragmatic logic, meaning that he followed the simplest way, kind of like his policies aimed at increasing the average intelligence of the Kharbranthian populus.
Can't wait to get this cracked!