Just today I was browsing through the thread with all the old photo's from the U-boats, and I was thinking about a way to make those air-intake thingies myself. I guess I don't have to worry about that anymore.
btw, how did you make this? Did you somehow add them with s3ditor?
I thought about adding those things to the conningtower .tga file, but that would require a different way of unwrapping the model I think; something I'm not really good at.