I would say we have substantial quantities of already-smelted metals, readily accessible. In a post-apocalyptic society, the need for materials is likely to be between somewhat and a lot less that today, because we would be designing and building things to be used for a while, rather and building things to have the shortest possible journey to the midden. What has already been produced could maintain a post-consumerism society for quite a while.
Also, such a society would probably not have a strong objection to using hemp for many of their fiber-related needs. Hemp is just this side of being a total weed, so it should be fairly easy to grow and harvest.