The final two steps were to apply two different tones of dust pigments to the roads for even more surface variation, and then give everything one final coat of Bergswerk's Matt Varnish applied with the airbrush.
Here is the complete set.
This is how the interlocking of the tiles looks like from close up. Some of the cobblestone tiles' jagged edges project over the MDF-base, the more recessed ones leave ~2mm of MDF showing. So there is no gap between tiles where you can see the underlying surface; the gap you see only shows the underlying MDF which was painted a very dark brown/black.
The connections are not invisible, but could be much more obvious.
The scenarion I want to use them for will have a layout similar to this setup:
Some closeups of the statues:
Overall I am quite happy with the result; the only thing I would wish for is for the roads not to look this angular. But this is inherent in using square cast blocks.