Loved that show - the tank reminds me of the one in the opennig scenes of the 2004 Appleseed movie. Only the front 2 sets of wheels were spherical on that one though, I think. I'll need to watch it again.
Boneparte was around way before the animation; in the Manga - Dominion: Tank Police
The design changed a little, but was basically the same little guy...... There was a really nice kit that came out a few years ago - Not very big, but the detailing was nice.