(Sadly though, Malamute's beautiful church doesn't have a bell in the bell tower (such a slapdash attitiude
) are you going to put a bell in that little aperture at the top of the facade?) 
Of course! A church without a bell is not a church ... ask Malamute about that

I am still searching for a bell? Anyone any ideas??? I thought about a wooden horizontal post in the aperture and the bell hanging down from it. On top of the rounded wall a black wrought-iron cross will be added.
@ gamer Mac:
You are right. The blue and green material is high density foam. I bought it in a nearby shop that sells architectural and model building materials (Kirch Modellbau, homepage:
http://www.kirch-gmbh.de/index_home.html). It is (in my opinion) not very expensive. For example a piece of 600mm x 330mm, 5mm thick costs Euro 3,50.
@Mikey:
The plaster is a very "wet" mixture of what we call "Rigips" in Germany (
http://www.rigips.de/putze_handputze.asp#pos1). The page is available only in german ...
We use this plaster normally inside houses on walls and in the corners to close all holes before putting on wallpaper or stucco. When it is mixed with water to a very wet consistency you can put it on with a brush (it is easier to reach corners for example).
Thanks for the motivating remarks ... hope to finish it very soon.