Trente-Trois was Buster Machine 33. It was partnered with Dix-Neuf in the Second Kuiper Belt Naval Battle. It was however lost in that same battle. Years later it's remains were found on Pluto by Casio, which he kept to himself until sharing his secret with Nono.
Trente-Trois was never depicted in it's former glory. In current day Trente-Trois is a skeletal heap on Pluto, having wasted away over time.