15thc perception on swallowtail merlons?

[Koen G]

That's why I'm asking for some "proof of historicity" in this thread. I think there are two main reasons why merlons are often unreliable:

1. The top of structures will crumble first and require restoration sooner. 
2. Merlons are a dramatic part of a structure and subsequent owners would often update them to their preferred style. This happend a lot in the age of romanticism for example.

With many of the Italian castles we have the advantage that the merlons are so clearly part of the crumbling original building.