You didn't you see Cobra Commander being chromed after the fact?
What about T1 Arnold's shirt being changed?
Those are paint and fabric changes. Not changes to the sculpt. You would have to make the hands and cane removable. Then you have to add magnets (if they aren't being used already) along with a new set of hands and the hammer. Do you really expect SSC to pick up the cost for that? Remember that the price is set and the EX is sold out. That would mean that SSC would have to eat the additional cost of the hammer on an already sold out and very popular piece. I don't see that happening.