I'd say the swap is the best bet, especially since you've already got a donor. Maybe the cut case could have a bigger hole cut for a window? Could be better looking at least, either to show the guts of a Classic, or perhaps in building a Macquarium? Just trying to think of things to do with that hole... I kind of like that Macquarium idea with a side window. At least you wouldn't feel bad hacking up that case.