I don't have an IBM, so I can't speak about whether the wire puller will work just as well for that one.
As far as typing, I actually don't rest my wrists while I'm typing. It's only when I'm between writing (i.e. thinking of the next thing I'm going to type). If I'm just transcribing, my wrists never go down. That's why I am going to get one of the flat wrist rests people recommended, because it will likely be like the plastic ones on my old keyboards. They don't get in the way when I lift my wrists up, but they are there to set my wrists down.