Nifty idea... great starting point in my opinion. Obviously (as you've already said) it's not definitive and would require further testing to get it perfect but this should get you into the right ball-park.
I'd guess gutting standard pipes would give about the same value as TOR's (+3). What value for a freak kit then? +10 since it's similar to a drilled 'box + removed snorkle? Maybe a little more... +12 perhaps? I like that you've included a 0 for the AI, would stop the constant repitition of "what value is the AI?"
With a little input from the "old & wise" this should go into the tech vault, in my humble opinion.
Matt
