Water table: when you remove the barrels from the action you can see the flat horizontal area of the action that the barrels rest on. That is the water table and will have some assorted stamps/marks/numbers on it. There will also be similar stamps on the bottom of the rear portion of the barrels (barrel flats) that would rest on the action's water table when gun is assembled & closed.
You should also look/photograph the bottom of the action, where the trigger guard is. There may also be some writing that might mention a model description. You should also look carefully all around the engraving for a, possibly very small, inscribed Italian name. That could be the name of the engraver.
Articulated trigger; The front trigger would be made with a sprung hinge allowing a slight forward movement when pressed from behind.
