Hans Wrote:
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> Irregular, uneven, different sizes, 'lumps'

Yes. Do you see how the joints have the same air-gap through their irregular shape? The shape of one block at the joint follows exactly the neighbor block at a fixed distance. That's explained by the shrinking over time during completing the curing process. It would be a ridiculous amount of work to manually shape each block's irregular side surface to fit the neighbor's irregular side surface. With the pouring process and using an existing block as one side of the mold, it solves the problem automatically without additional work.

You may now say that the wooden molds Davidovits uses in the video have flat surface. Yes, that's true. But he could also have used flexible molds from fabric or leather.

> Do a very careful examination of these stones in the GP which ones are poured?

All of those I see in that old photo. You can see interesting small details of the pouring process in some, like layers of air bubbles.

> They are pretty much all individualistic

Correct. As explained by the process when using flexible molds.