While the wine boxes are really impressive I'm more interested in the lowly cobble stones as they lend themselves so well to a dio I had long planned for but was too lazy to make my own cobble stones.

That type of cobblestone (rectangular) would be the easy one to make. Cut some from Styrodur/XPS/Hartschaum (Proxxon helps but is not needed), texture with balled up tinfoil, use them to make a silcon mold or three, pour using Stewalin. Or if you do not want to pour (but THAT really needs a Proxxon hotwire table) cut them by the dozends.