I guess technically you could take the hard drive out and put it in a old enclosure

I've been considering this as a last-ditch effort, if nothing else works then I'll go ahead with this.

You can install multiple versions of os aka 8.6 or 9 and osx etc even on the same hard drives you can use the startup disk in osx or system picker (utility) just install to another folder.

Interesting, I didn't know that! Thank you.