Apologies for the double post (almost twelve hours after the above post, so I think I'm okay) but I don't need help any more. I just did the upgrade, and even though I spent most of the time bricking it, I now have so much moar breathing space on my PS3 console. Managed to do everything without many problems, so it was a success without my thought processes above. YAY.

Still curious if it'd work though, but I doubt it will. Posted the same thing on another forum, and most of them said it wouldn't work.