Jeremy, from your post it sounds like the poor condition of a foundation was concealed by a previous owner by an interior (frame?) wall placed inside the brick foundation. From your description, the house is settling due to a deteriorating foundation and causing the wall to buckle. You are looking for ways to either reinforce the foundation with steel plates or perhaps considering jacking up the house and rebuilding the foundation.
Since the whole investment which is your house is resting on this unstable brick and a buckling interior wall that is not even supported by a footer, you really need a professional foundation contractor or structural engineer to advise you...NOW! Such projects are certainly out of the question for even the most experienced DIYer and a good many non-specialized contractors. You need to determine not only the current structural condition, but the factors that led to significant deterioration. Lets face it, 50 years is not a long time in terms of a foundation. Good luck and don't wait too long.