It would seem that there is some open source software that would allow you to create objects of a certain volume, even with arbitrary shape (I'm thinking blender and some of it's addons.)
Now, I know that, to spin, a top has to be symmetrical. However, does is have to be radially symmetric? (Or how close does it have to be?)
I think I saw a top that consisted of a long spindly basketball player being spun (but if you saw all the empty space it was radially symmetric at most angles.)
I'm not a math genius but I did just barely survive 10 credit hours of calculus based physics, so if you are willing to explain it a bit I'll knock myself out...