Hi, I have changed about 4 floppy drives on WK4 and they are the same as you use on a normal PC so If I where you I'll go for that and replace it yourself, it's very easy to replace. But before you buy 1 I suggest that you open the keyboard and take it with you when buying a new one, because there are some Floppy disks that the connecting port is on the other side and so the connecting cable won't reach that far. If that is the case and can't find one like it, you have to buy a longer cable.

Hope I've explained myself enough
Good luck.

Tony.