15thc perception on swallowtail merlons?

[Koen G]

Let me see what I can find. 
For the image top left with Habakuk, You are not allowed to view links. Register or Login to view. gives Auer, Italy, 1444. It's probably reliable.
Google does not help me find any of the other images, do you have a source?

[Aga Tentakulus]

@Koen
Unfortunately I can't give you any more hints about origin. Have completed my research of the battlements for years.
Find it but super if it is properly documented.

The one in your link is correct. Below still "Daniel in der Löwengrube".
The sky and the stars is an excerpt from a painting. The blue sky is a flag. The view is under the flag.

[Aga Tentakulus]

   

@Koen
You write that many battlements were covered during renovation work.
Have here another beautiful photo. (somewhere in the Tyrol)

[CaryR]

         

These two images are potentially interesting. I originally found the first one on Pinterest, which comes from this You are not allowed to view links. Register or Login to view. about medieval gardens that just says it's an engraving. I tried a reverse image search but couldn't find original sources anywhere. Then I found the second image, which is similar but again there are no sources. Just throwing that out there in case anyone else has any luck tracking down more info. But it may be a dead end, and the dates of their creation are unknown.

[Koen G]

I can't quite place the art style, but the relatively realistic way the animals are drawn makes me suspect it's quite a bit too late for our purpose, probably 16th century. 

Going by the iconography, I'm pretty sure this is St Francis of Assisi preaching to the birds. But this doesn't seem to help much in tracking down the image...
Edit: sites where it appears tend to use it as an illustration of the "hortus conclusus", so it is probably not St Francis after all, but rather a monk enjoying the walled garden. None of them seem to mention sources though.

[Koen G]

I think I found it: You are not allowed to view links. Register or Login to view.

FIORE DI VIRTÙ -- FIOR DE VIRTU utelissimo acadauno fidel Christiano. Venice, Christophorus de Pensis de Mandello, April 29th 1500.
...
The Flower of Virtue is an anthology of moralizing content drawn up in the early fourteenth century by a certain friar Tommaso, who lived between the late thirteenth and early fourteenth century. The collection, of which well over one hundred manuscripts are known, had a great success and was re-proposed in more than thirty editions of the fifteenth century and translated, even several times, into numerous languages. Reprint of the edition of April 24th 1500.

[CaryR]

The Flower of Virtue is an anthology of moralizing content drawn up in the early fourteenth century by a certain friar Tommaso, 

...

Oh, well found! From this You are not allowed to view links. Register or Login to view., I see that this MS used the swallowtail merlons in another You are not allowed to view links. Register or Login to view. too:

   

(It's still a bit late though, 1495)

 

[MarcoP]

These could all be the work of a single painter: Giacomino da Ivrea, a travelling artist, though with a limited range. Most images are from You are not allowed to view links. Register or Login to view., Carlo Naldi.

Ivrea, before 1437:
   


Marseiller (Verrayes) You are not allowed to view links. Register or Login to view., 1441:
   

Marseiller (Verrayes) Saluard fortress (unknown date, but possibly close to 1441?):
   

Gressan, 1463:
   


From You are not allowed to view links. Register or Login to view., I understand that the frescoes in the You are not allowed to view links. Register or Login to view. (Bourg-Saint-Maurice) were also painted by Giacomino. You are not allowed to view links. Register or Login to view. they are dated to the third quarter of the XV Century. Apparently, Giacomino also worked in Geneva, but I have been unable to find more details.
   

[Koen G]

Great addition, Marco! If we keep the boundary of 1450, then I add Ivrea and Marseiller, that may be a good balance?

[MarcoP]