New item: dueling shields
Dueling shields are tower shields with hooks and spikes, used in medieval Swabia.
The dueling shield is both a shield and a two-handed weapon, and it should train both those weapon skills. Suggested stats: DV, PV, and weight similar to the tower shields; damage (+n, 2d6+n) with n = 1, 3, 7, 12 for the iron, mithril, adamantium, eternium shield.
Edit: I attached a couple of images grabbed from the web.