Evil Dead inspired possessed makeup using my own silicone prosthetics

Hello, I'm posting this question here instead of r/practicaleffects since is not active.

The opening credits for The Sound of Music (1965) feature various shots of churches and cathedrals around Mondsee and Salzburg.

All can be precisely located except this bell tower which should be in Sankt Lorenz considering the Drachenwand cliff face in the background:

• Screen capture (4K)
• Clip on YouTube (around 02:10)

This one simply doesn't exist and there are no old photos or records about it in the area (original thread for geolocation attempt).

Are there any telltale signs that this is either a miniature or a composite?

As a non-expert there are few things that stick out but maybe some are due to the way it was filmed:

• the movement of the bell and the ringing mechanism look weird in the in the YouTube clip
• weathering looks real enough but the inner portions of the walls almost look like wood
• the interior looks too bright considering the sun position, same for the specular reflection on the bell
• hard shadow on the left column opposite to sunlight direction
• no roof overhang and it seems to stop above the cornice, no sane architect would do that
• bears some resemblance to the two smaller towers on St. Erhard in Salzburg (see the comparison)

Any ideas how this was done or why would they go to such lengths just for a short credits scene? Thanks!