Well the Duo 230 is in very good condition cosmetically so it's too good to be classified as a junk machine for ripping in to, I would feel bad about completely breaking it. And seeing as we think it has no hard drive, there's no way I could get it working anyway (and the fact that the screen is probably dead or it needs a new capacitor or something like that, neither of which I could possibly deal with either). The only machine I would be happy to rip into as a training machine would be something that really was scrap, like a 286 laptop with a caved-in screen or something like that which (1) has any chance whatsoever of working again, (2) is not a machine that you feel has some sort of "character" (like the Macs always seem to) and (3) is not something that has any value that you could realise by selling it as a parts/repair machine.

I'll test the Zip drive when I have the chance, to see if that has come back from the land of the dead or not. Best to start small eh? (of course that fulfilled the 3 criteria above, so I didn't feel bad about opening it up as I was only going to throw it away anyway)

I am now just about confident enough to do light upgrading of a working desktop Mac (I did some stuff in the G3 for instance), but never a laptop.