Really well done!
They are beautiful models, with the scent of an architectural drawings sketched by hand and with very carefully designed details, including the interiors and ceilings of the sotoportego type passages through the buildings. I found myself the chimneys to be the most tricky, but it is really difficult to make them less flat that they are designed.
If you are not a historical correctness purist yourself, you can supplement the Venice diorama with the Rialto bridge free paper model available at
link .
This bridge was built in 1580s and 1590s so it corresponds well with the architectural frame of the city of 1575.