The graphics do show up properly if you build the building in the game (i.e., once you get the game started), but they show up wrong (as whatever the default culture is) if you place the building by descr_strat.txt or campaign_strat.txt. This makes me think it has to be something else, though it makes me feel a little better to hear someone else has the problem even under different circumstances.

BTW, when I change the default culture to roman again, it just shows whatever the roman variant of the building is - the problem remains, it is just transferred to a new culture.