Hi Zwerkules! About that building, I don´t remember it very well from my playtrough of NWN2, but thinking about... maybe from some part of Illefarn ruins?
Anyway, I think that the most important thing in a building like that if it is in ruins is the roof... Is like crystal! When you said that you adapted from a ruined versión I was thinking that the original model would be something like a broked dome type building.
However, I think that I am going to introduce your model in my module, if you think that´s okay. Later, I will retexture the walls with my favourite decrepit stone texture, hang some ancient vines here, there... God, I love ruins. Maybe too much...