That will look awesome, the louvers will look great too. If I had a louver press, holy crap, I think every piece of metal around my house would have louvers in it whether it looked good or not. Cabinets, cars, trucks, tables, electrical boxes.... haha
Also, did you say you are using a poster board like cardboard for the shaping of things? It looks like it from the pictures but not sure if it is as thin as I am thinking.