Call me stupid, but I tore apart the bullnose out of my U-673. (The forward upper tip of the bow.) This after the nose was all completed, filled, and primed. I had a piece of brass tubing CA'd through the plastic hull, so removing it was... fun. I ended up cracking the top part of the deck at the nose. Arrggghhhh! Of well, a quick application of epoxy putty gave me a fresh surface to start again.
I just wasn't happy with the bullnose I made... the inlet is still too small.
After looking at my Type VIIC "Warship Pictorial" book again, I found a few *excellent* pictures of the bullnose inlets (esp. on page 34). I'll be reconstructing the bullnose this week, using a much larger inlet depicted in the photos.
The bullnose inlet on the stock VIIC kit is about 1/4 the size it should be, and is too far back from the tip of the nose.