[withinboredom]

Well. Sure. If we move the goal post to “something passable and good enough” you only need a small number of people. In that sense, we are lucky that “black smithing” (as a proper trade) only ended in the last hundred years and many people continue it as a hobby. In that case, “small team of hobbyists” can likely reproduce a few bricks. But bootstrapping mass production of bricks? Unlikely.