I'm not sure about that ships bell. Is it removed before submerging or is it for waking Neptune from his sleep... or the Kraken...? Also why is the front of the conning tower so unergonomic - or is that for the funnel... er, I mean snorkel thingy?
The bell honour boards and all the harbour tiddly things were taken done below on sailing.
Yon funny thing on the front of the fin was the blowpipe missile system which Shorts thought every submariner would want, and were quite surprised when, after spending all your and my money, they found out that no submariner in his right mind wanted one.