Thanks! This nicely fills out the map a bit further.

The frescos were already on the map as "Castello di Avio".

The one in Austria looks like a typical example of restoration swallowtails - it's hard to know if they were there originally as well.

Were already on the map: Arco, Sirmione

Added: Drugollo, Malcesine, Hocheppan, Riva del Garda, Vignola (to castles layer), Ried, Schlanderberg

Not certain of chronology of building layers: Mantua Palazzo de la Ragione, Brunnenburg (looks restored). 

I would have doubted Churburg - this would be our northernmost example, and the merlons look very clean. I will add it unless Royal Swallowtail Inspector Peter Tentakulus knows of a reason not to 

(PS: Schwalbenschwanzzinnen is one of those German words that must look crazy to English speakers).