Well, the cake turned out to be a success. Not only was everyone at work very impressed, but I got praise from a random bus company employee in the city on my way to work who particularly liked the ship. So that was nice, if slightly bizarre and unexpected!
I think the key sign of success, though, is that by this afternoon, there was only one piece of cake left. Which, of course, was when the Boss Man decided to do one of his periodic walk-through-and-chat-with-employees things. The conversation went something like this:
Boss Man: Hello! How's it going? Oooooh, cake. Is it someone's birthday?
Me and Colleague: Melbourne's!
Boss Man: Um... What?
Me: Yesterday was the 175th anniversary of the founding of Melbourne.
Boss Man: Oh. And who made the cake?
Me: That would be me.
Boss Man: Were the colours [the remaining piece had part blue, part green icing] representative of anything?
Me: Well, the cake was a map of Victoria, Tasmania and Bass Strait with the boat in Bass Strait representing John Pascoe Fawkner's trip from Launceston to what became Melbourne!
Boss Man: Well. That's quite some...dedication??...to Australian history... *slightly terrified expression*
Colleague: Sooooo... *quickly changes the topic*
Me: *sits in my corner and shuts the hell up*
[After Boss Man has left]
Me: I just became the crazy girl who represents history in cake, didn't I?
Colleague: Yes. Yes, you did... Sorry dude...
I may have paraphrased or reworded a few bits of that, but the overall gist remains accurate. In hindsight, I should have given him the last piece of cake. Then the sugar high from the icing would have made me seem less weird... ;)