I don't think that Industry and Slavery are perfectly analogous. Like I said before (in the aforementioned post), there are no perfect analogies in history. By nature, history doesn't allow for it: history is a sequence of absolutely unique events. History is not a science, and we cannot treat it like one. As N.T. Wright pointed out - in one of his Christian Origins books; I'm not about to flip through thousands of pages to tell you right now, but it was probably The Resurrection of the Son of God - 'Caesar's Crossing of the Rubicon' happened once and for all; it is not the sort of phenomenon you can repeat and therefore test. Science, an empirical art, requires exact duplication. History forbids it.
I digress. So Industry and Slavery are unique in history and not perfectly analogous. That doesn't mean we shouldn't be learning by comparing them, because all analogies must at some point break down, anyway - but not necessarily before they prove their worth.