Ohh yes, we feel your pain...take a look here :
you can start on post 85, or take a peek before it ...However we faced the same issues. 4 coats of paint, and the one "unknown" one layer was burnt on due to an electrical fire. It was a bear to take off. However Citri Strip works very well. We took 3 passes with it and we are right on the mark, some touch up needed in parts.
If you are having trouble with getting the remaining stripper off the tracks or window edging, try a fine 4" wire wheel on a drill. Use a lower grade if you are going to prime and paint.
Best of luck on your project. You folks are not that far away, you can always stop be for a visit....maybe we can put you to work ...ok ...I know, nice try...