;-) It depends upon what needs to be swapped. If it is just the mechanical parts for the F6 key, then there should be no problem.
:-( If the circuit board itself is damaged, then I suspect that the A1200 board will not connect electrically to the 4000 without an adaptor of some sort.
However, the insides of the A3000 and A2000 keyboards are identical enough to be interchangeable with the A4000. For what that's worth.