Looking at Mcdermd's picture it looks like you'd pretty seriously compromise the structural integrity of the Duo trying to fit that in there. I suppose I have to ask, since I never owned one... is the Duo keyboard *really* horrible enough to merit the level of destruction it'll take to get an alternative in there? The Powerbook G4 keyboards aren't exactly fabulous either. (Not terrible by laptop standards but... not great either.)

Just spitballing, how about a NetBook keyboard? Something like this looks to be about right, perhaps a little on the small size going by the stated external dimensions of the two systems?