Nope.
It's not a mater of physical size, as that most likely would work. It's a matter of proper position of the keyboard ribbon cable in relation the motherboard, and if there is a backlight connector on the motherboard (possibly power consumption too?).
The only model that I know of with swappable keyboards, and someone please correct me if I'm wrong, are the Late 2008 2.0 Ghz model (non-backlit) and late 2008 2.4 model (backlit). Most, not all, 2.0 Ghz motherboards had the backlight connector on motherboard, and the keyboard ribbon cable was in same position on both. The non-backlit keyboard would fit on the higher end computer, obviously no backlight.