Seems as though your current doctor is trying to figure out a reasonable and appropriate means to address your pain mangement needs. If he is satisfied the leads have not migrated, perhaps he is trying to figure out how best to "get it running again." Anyway, if he is able to replace the computer/battery unit and connect to your existing leads it sounds like replacing a worn and nonfunctioning car part, hooking it into the rest of the works to restore you to functionality. Wow, I guess this kind of begs teh question whether physicians will, in the futere, come to be known more as mechanics.....
Time to ask questions of your doc whether the replacement of unit maneuver will restore operatino through the well positioned leads. I do not understand the movement of that base unit concept, but your doc should be able to fully explain what is behind that suggestion.
Nevertheless, you will assuredly be in our thoughts and prayers here, both during this time of pain management without the unit and through restoration of a working stim for you!
Prayin,
Mark56