Mike, Open Transport isn't used in OS X. Do you have Classic installed? See:
http://en.wikipedia.org/wiki/Open_TransportI don't know what is really missing - have you tried doing an archive and install? And why are you still running 10.3.2 on the external drive (just curious...)?
When exactly do you get this message? What do you mean when you say "serious failure" - what failed? What is/isn't working now? More info needed methinks, in order to track down this issue.
I've had a look on my Mac and there is nothing called "OT..."