My cardboard shell came out somewhat adequate.  Overall, I found myself just going along with what the cardboard wanted me to do, rather than the other way around.  The form itself started to become a little skewed near the upper third.  It tiled to the side, and didnt have the same coherent swirl as before.  The top opening was a valiant effort, but overall I wasnt pleased with it.  It helped it resemble a shell somewhat, but just didnt capture the swirling feel of the original.  Finally, the spikes were a decent addition, that honestly pulled the whole thing together, because without it, it hardly looked like a shell at all