Sorta. Take a look at a brick in a house. You'd need everyone from geologists to miners to kiln specialists to construction workers and engineers -- not to mention all the people required to make the tools required to make the tools. The team would likely involve well over 1000 people. So, "just assemble a team" is not quite as simple as you make it sound.
I don't think that's true in the sense meant. Sure, to reproduce a near replica of a specific brick from first principles. But not to produce something broadly functionally equivalent. You can (rather inefficiently) manufacture approximately equivalent bricks in your backyard on your own, possibly even from locally harvested material depending on where you live.
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.
Doesn't matter. At the end of the day, the knowledge is embodied by humans, or can be learnt again. Let it be 100, 1000 or 10000 people. At the end of the day, they are made of meat.
When you let the machines do it, and don't care about moving it towards human domain (i.e. meatspace), you're done.
